2005 R53

Ok so late last fall my car started running poorly and progressively got worse. So I bought a Screamin Demon coil along WMW plug wires and the colder NGK plugs because I knew I was getting the 15% pulley soon. The car sprang to life and I was a happy camper. Not long after that my stock exhaust manifold broke in half right above the Cat.

So instead of getting another stocker I found a stainless steel, less expensive one on Amazon. It also came with a high flow cat which I used. Now I live in Indiana so emissions are not a problem. But ever since I installed this new exhaust manifold with the new Cat, the SES light is driving me bonkers. I scanned it and code P0130 and P0133, meaning bank 1(pre-cat) O2 sensor. So I bought the NGK OEM to replace it. Cleared the codes again and it was fine for 4 days then the SES light came back....again with the exact same codes. I finally did install the new pulley from WMW but have not really noticed much difference in power, I do hear the beautiful whine at higher RPM's though.

And ever since the exhaust manifold install, the car idles fine for like 10-20 secs and then the RPM's start dropping and it sounds like its going to stall but it never does. It pulls out of the low RPM's and idles fine for about another 10-20 seconds and then the cycle starts all over again. I have cleaned the TMAP and MAP sensors with MAF cleaner but no difference. I bought the car used in 2015 and am not really sure of the car's history. It had an aftermarket swaybar and M7 front shock tower reinforcement plates but other than that, that's it. She currently has 136k miles on her.

Its just frustrating trying to nail this one down and I know the car should run better than this.

Any advice would be greatly appreciated!!

 

bump!