Long story short a buddy installed shorty headers and a catless y-pipe on his 2011 ranger. When he did so he broke an exhaust stud off into the block. I welded a nut on it got it out, we finished running exhaust, and were planning to upload a tune file deleting the EGR codes, rear O2s, correcting tire size, and raising speed limiter. However, as soon as we got it back together I noticed it was running like garbage. I hooked my laptop up to do some diagnosing and it looks like the O2s are reading strangely. It's like when the truck first starts up they bounce around voltages almost like normal then within 15-20 seconds they start to show a drop in voltage until they are down to .003. This then sends the STFT to 66.4% and the truck begins to run like horribly, also popping codes for both banks being lean. It will start idling like it's cammed, doesn't accept throttle input well, and tries to stall. We went and bought brand new sensors and it did the same thing. I tried uploading my tune file with the above done and it did the same thing. There is a small exhaust leak on the bank 2 side just above where the O2 sensor bung is but it's very small and the other side has no leak that I can tell. So I am assuming this isn't just air coming in and messing with the readings but I could be wrong.


Attached is a log file, any help would be greatly appreciated. Also if anyone that actually knows how to tune these trucks is interested in doing some remote tuning I believe he would be willing to exchange monies.Pinto Stock tune weird O2 readings.hpl