diff --git a/modules/openapi-generator/src/main/resources/r/api_doc.mustache b/modules/openapi-generator/src/main/resources/r/api_doc.mustache
index 17c3bdc1e91..a9604172115 100644
--- a/modules/openapi-generator/src/main/resources/r/api_doc.mustache
+++ b/modules/openapi-generator/src/main/resources/r/api_doc.mustache
@@ -68,16 +68,20 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  {{#errorObjectType}}
+  # error object
+  dput(result$ApiException$error_object)
+  {{/errorObjectType}}
 } else {
   {{#returnType}}
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   {{/returnType}}
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 {{/useRlangExceptionHandling}}
 {{/returnExceptionOnFailure}}
diff --git a/modules/openapi-generator/src/main/resources/r/api_exception.mustache b/modules/openapi-generator/src/main/resources/r/api_exception.mustache
index 76473661503..64aa6c3d76a 100644
--- a/modules/openapi-generator/src/main/resources/r/api_exception.mustache
+++ b/modules/openapi-generator/src/main/resources/r/api_exception.mustache
@@ -9,7 +9,7 @@
 #' @field body Body of the http response
 #' @field headers Headers of the http response
 {{#errorObjectType}}
-#' @field errorObject error object type
+#' @field error_object error object type
 {{/errorObjectType}}
 #' @export
 ApiException <- R6::R6Class(
@@ -20,7 +20,7 @@ ApiException <- R6::R6Class(
     body = NULL,
     headers = NULL,
     {{#errorObjectType}}
-    errorObject = NULL,
+    error_object = NULL,
     {{/errorObjectType}}
     #' Initialize a new ApiException class.
     #'
@@ -42,7 +42,7 @@ ApiException <- R6::R6Class(
         self$headers <- http_response$headers
         self$reason <- http_response$http_status_desc
         {{#errorObjectType}}
-        self$errorObject <- {{errorObjectType}}$new()$fromJSONString(http_response$response)
+        self$error_object <- {{errorObjectType}}$new()$fromJSONString(http_response$response)
         {{/errorObjectType}}
       } else {
         self$status <- status
@@ -50,7 +50,7 @@ ApiException <- R6::R6Class(
         self$body <- NULL
         self$headers <- NULL
         {{#errorObjectType}}
-        self$errorObject <- NULL
+        self$error_object <- NULL
         {{/errorObjectType}}
       }
     },
@@ -76,9 +76,9 @@ ApiException <- R6::R6Class(
         errorMsg <- paste(errorMsg, self$body, "\n")
       }
       {{#errorObjectType}}
-      if (!is.null(self$errorObject)) {
+      if (!is.null(self$error_object)) {
         errorMsg <- paste(errorMsg, "Error object : ", "\n", sep = "")
-        errorMsg <- paste(errorMsg, self$errorObject$toJSONString(), "\n")
+        errorMsg <- paste(errorMsg, self$error_object$toJSONString(), "\n")
       }
       {{/errorObjectType}}
       errorMsg
diff --git a/samples/client/petstore/R/R/api_exception.R b/samples/client/petstore/R/R/api_exception.R
index e198854bf34..77b1d26d111 100644
--- a/samples/client/petstore/R/R/api_exception.R
+++ b/samples/client/petstore/R/R/api_exception.R
@@ -14,7 +14,7 @@
 #' @field reason Reason of the ApiException
 #' @field body Body of the http response
 #' @field headers Headers of the http response
-#' @field errorObject error object type
+#' @field error_object error object type
 #' @export
 ApiException <- R6::R6Class(
   "ApiException",
@@ -23,7 +23,7 @@ ApiException <- R6::R6Class(
     reason = NULL,
     body = NULL,
     headers = NULL,
-    errorObject = NULL,
+    error_object = NULL,
     #' Initialize a new ApiException class.
     #'
     #' @description
@@ -43,13 +43,13 @@ ApiException <- R6::R6Class(
         self$body <- errorMsg
         self$headers <- http_response$headers
         self$reason <- http_response$http_status_desc
-        self$errorObject <- ModelApiResponse$new()$fromJSONString(http_response$response)
+        self$error_object <- ModelApiResponse$new()$fromJSONString(http_response$response)
       } else {
         self$status <- status
         self$reason <- reason
         self$body <- NULL
         self$headers <- NULL
-        self$errorObject <- NULL
+        self$error_object <- NULL
       }
     },
     #' Returns the string format of ApiException.
@@ -73,9 +73,9 @@ ApiException <- R6::R6Class(
         errorMsg <- paste(errorMsg, "Body : ", "\n", sep = "")
         errorMsg <- paste(errorMsg, self$body, "\n")
       }
-      if (!is.null(self$errorObject)) {
+      if (!is.null(self$error_object)) {
         errorMsg <- paste(errorMsg, "Error object : ", "\n", sep = "")
-        errorMsg <- paste(errorMsg, self$errorObject$toJSONString(), "\n")
+        errorMsg <- paste(errorMsg, self$error_object$toJSONString(), "\n")
       }
       errorMsg
     }
diff --git a/samples/client/petstore/R/docs/FakeApi.md b/samples/client/petstore/R/docs/FakeApi.md
index 484ca98a1d6..558584fe697 100644
--- a/samples/client/petstore/R/docs/FakeApi.md
+++ b/samples/client/petstore/R/docs/FakeApi.md
@@ -31,14 +31,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
diff --git a/samples/client/petstore/R/docs/PetApi.md b/samples/client/petstore/R/docs/PetApi.md
index f094099bd54..0a156275691 100644
--- a/samples/client/petstore/R/docs/PetApi.md
+++ b/samples/client/petstore/R/docs/PetApi.md
@@ -41,14 +41,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -101,12 +103,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -160,14 +164,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -221,14 +227,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -282,14 +290,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -346,14 +356,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -408,14 +420,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -471,12 +485,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -533,14 +549,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
diff --git a/samples/client/petstore/R/docs/StoreApi.md b/samples/client/petstore/R/docs/StoreApi.md
index 31343a84ea0..b7910812681 100644
--- a/samples/client/petstore/R/docs/StoreApi.md
+++ b/samples/client/petstore/R/docs/StoreApi.md
@@ -31,12 +31,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -89,14 +91,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -144,14 +148,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -204,14 +210,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
diff --git a/samples/client/petstore/R/docs/UserApi.md b/samples/client/petstore/R/docs/UserApi.md
index 3382f734cef..a9d8a646d90 100644
--- a/samples/client/petstore/R/docs/UserApi.md
+++ b/samples/client/petstore/R/docs/UserApi.md
@@ -37,12 +37,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -93,12 +95,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -149,12 +153,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -205,12 +211,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -262,14 +270,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -323,14 +333,16 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # deserialized response object
-  response.object <- result$content
+  dput(result$content)
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -382,12 +394,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
@@ -436,12 +450,14 @@ result <- tryCatch(
           )
 # In case of error, print the error object
 if (!is.null(result$ApiException)) {
-  cat(result$ApiException$toString())
+  dput(result$ApiException)
+  # error object
+  dput(result$ApiException$error_object)
 } else {
   # response headers
-  response.headers <- result$response$headers
+  dput(result$response$headers)
   # response status code
-  response.status.code <- result$response$status_code
+  dput(result$response$status_code)
 }
 ```
 
diff --git a/samples/client/petstore/R/test_petstore.R b/samples/client/petstore/R/test_petstore.R
index f5c7843bc4f..40b2f358802 100644
--- a/samples/client/petstore/R/test_petstore.R
+++ b/samples/client/petstore/R/test_petstore.R
@@ -49,27 +49,28 @@ dput(result)
 ##a <- ModelApiResponse$new()$fromJSONString(errorMsg)
 ##dput(a)
 ##
-##var_pet_id <- 1231256 # integer | ID of pet to return
-##
-###Find pet by ID
-##api_instance <- PetApi$new()
-### Configure API key authorization: api_key
-##api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
-##result <- tryCatch(
-##             api_instance$GetPetById(var_pet_id),
-##             ApiException = function(ex) ex
-##          )
-### In case of error, print the error object
-##if(!is.null(result$ApiException)) {
-##  cat(result$ApiException$toString())
-##} else {
-##  # deserialized response object
-##  response.object <- result$content
-##  # response headers
-##  response.headers <- result$response$headers
-##  # response status code
-##  response.status.code <- result$response$status_code
-##}
+
+## Test exceptions
+var_pet_id <- 1231256 # integer | ID of pet to return
+#Find pet by ID
+api_instance <- PetApi$new()
+# Configure API key authorization: api_key
+api_instance$api_client$api_keys['api_key'] <- 'TODO_YOUR_API_KEY';
+result <- tryCatch(
+             api_instance$GetPetById(var_pet_id),
+             ApiException = function(ex) ex
+          )
+# In case of error, print the error object
+if(!is.null(result$ApiException)) {
+  cat(result$ApiException$toString())
+} else {
+  # deserialized response object
+  response.object <- result$content
+  # response headers
+  response.headers <- result$response$headers
+  # response status code
+  response.status.code <- result$response$status_code
+}
 #
 #json2 <-
 #'{"name": "pet", "photoUrls" : ["http://a.com", "http://b.com"]}'
diff --git a/samples/client/petstore/R/tests/testthat/test_petstore.R b/samples/client/petstore/R/tests/testthat/test_petstore.R
index 9a0d059f56d..3132def5352 100644
--- a/samples/client/petstore/R/tests/testthat/test_petstore.R
+++ b/samples/client/petstore/R/tests/testthat/test_petstore.R
@@ -107,18 +107,19 @@ test_that("GetPetByIdStreaming", {
             )
 })
 
-#test_that("test GetPetById exception", {
-#  # test exception 
-#  result <- tryCatch(petApi$GetPetById(98765), # petId not exist
-#         error = function(ex) ex
-#  )
-#
-#  expect_true(!is.null(result))
-#  #expect_equal(result$toString(),"")
-#  expect_equal(result, "1")
-#  #expect_equal(result$ApiException$errorObject$code, 1)
-#  #expect_equal(response$name, "name_test")
-#})
+test_that("Test GetPetById exception", {
+  # test exception 
+  result <- tryCatch(pet_api$GetPetById(98765), # petId not exist
+          ApiException = function(ex) ex
+  )
+
+  expect_true(!is.null(result))
+  expect_true(!is.null(result$ApiException))
+  expect_equal(result$ApiException$status, 404)
+  # test error object `ApiResponse`
+  expect_equal(result$ApiException$error_object$toString(), "{\"code\":1,\"type\":\"error\",\"message\":\"Pet not found\"}")
+  expect_equal(result$ApiException$error_object$code, 1)
+})
 
 test_that("GetPetById with data_file", {
   # test to ensure json is saved to the file `get_pet_by_id.json`