Originally Posted by tom2112
Sorry I didn't see this sooner, BM. I also had the P050x codes (503 and 509 in my case, if I remember correctly). And the culprit was intake manifold gaskets. I had actually blow all six ports!
What a fun time that was. LOL
Rob will sort you out. He's the best.
No prob, thanks for the input! I got it solved today. The intake manifold gasket was the culprit! But I broke the IAT sensor in the process haha! Rob is getting me hooked up with one, should hopefully be in Friday!
Thanks for all the help guys. (And just an fyi, when the IAT sensor popped out on a test drive, it had pretty much the same symptoms)