I recently finished doing my H/C swap. I went with a set of ported LS1 heads and a TR224 on a 114 LSA cam. The car started right up, but after it warms up it won't idle, and the left bank is showing that it is lean (on a snap on scanner). ive replaced both primary O2 sensors. To get the car to stay running you have to keep your foot on the gas. Has anyone ever heard of this problem before? Any help would be appreciated.......

 

The most obvious issues would be exhaust leak; but it could be a vacuum leak at the intake causing the lean bank. I would start with a idle relearn (which is required if you disconnected the battery during the install) procedure to help with the idle, then check for vacuum leaks and exhaust leaks (check the header gasket on that side). Some idle surging is expected (but not that bad) when going to that cam without tuning.

 

A4 or M6?

 

I did have the battery disconnected and did not do an idle relearn, i'll try that....thanks. it is an A4. i don't think there is an exhaust leak but i'll double check.

 

You are probably going to have to have the idle speed raised (edited) at a minimum. I don't think C5s have a hole in the T/B blade stock. Might have to drill one as a crutch if you don't get an edit/tune.

 

hopefully, all i have to do is go through the idle relearn procedure, i won't be able to try it until monday. i have an appointment tuesday to have it tuned.