For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Check for any kinked exhaust pipes. Are there any kinked exhaust pipes? | -- | Go to Step 2 | Go to Step 3
2 | Repair or replace the exhaust pipes as necessary. Is there still excessive back pressure? | -- | Go to Step 3 | System OK
3 | Remove the muffler and visually check for restrictions. Are there any restrictions in the muffler? | -- | Go to Step 4 | Go to Step 5
4 | Replace the muffler. Refer to Muffler Replacement . Is there still excessive back pressure? | -- | Go to Step 5 | System OK
5 | Check for a crimped tail pipe or an obstruction in the tail pipe. Is the tail pipe crimped or obstructed? | -- | Go to Step 6 | Go to Step 7
6 |

1. Remove the obstruction or straighten the crimp in the tail pipe.
2. If the tail pipe is damaged, replace the muffler/tail pipe assembly. Refer to Muffler Replacement .

Is the exhaust system still restricted?

--

Go to Step 7

System OK

7 | Check for a plugged three way catalytic converter. Is there a plugged three way catalytic converter? | -- | Go to Step 8 | --
8 | Refer to Restricted Exhaust System Check in Engine Controls - 2.4L or Restricted Exhaust System Check in Engine Controls - 3.1L to diagnose the cause of the restriction. Is the exhaust system still restricted? | -- | -- | System OK