Ok so i do remeber back about 2 months ago I car would drop occasionally 500-600 rpm and even stall once in a while. For about 2 months prior had minimal problems with it stalling maybe 100-200 rpm drop when stopping. Then last week I changed all the piping in the exhaust along with a new hi flow cat thus far the car has created no engine code errors yet the thing stalls almost every time I go to stop then when I go to start the car makes a little black puff of smoke. This issue is kind of bugging me and wondering if anyone would have any suggestions or ideas at this point. also cylinder 4 is a little low on compression low meaning 60psi lower than the other 3 cylinders and all 3 cylinders are reading 230psi on a compression tester. Other than that it runs fine when driving even when its in boost i have zero issues mind ya she runs rich under boost. But i barley throw it into boost.

things i have done so far

Spark plugs.
wires.
icv
tb replaced
oil and fuel filter changed

Thanks

heated primary o2 sensor man. look in the performance forum for the thread, its a long read but in the end you will decide you need one.



M45/OS crank/2.4 snout. It's nice to be injected but I love being blown!

so use the Bosch sensor 15732 and re wire it as told from the sticky?