About 2 weeks ago I had a i/c pipe come loose at about 140mph. The car obviously went horribly rich instantly and ended up shooting a big ol fireball out the exhaust. I fixed the leak and car seemed fine. The next day the XEDE started clicking (probably just the glue coming loose). I went out on a 350-mile day trip and the car performed normally. On the way home on the interstate I got a CEL at 75mph under cruise. I went to Autozone and got the code read (the CReader that came with SMART never worked) and there were a pair of P0172s, "Bank #1 is running too rich". Next day I cleared the code and went on another long day trip, which including A LOT of hard running. Car performed perfectly as before, but once again on the way home I got a CEL at cruise. Same thing, a pair of P0172s. I clear em and call Vishnu. I talked to Dustin and he said the code means the long term fuel trim is too rich at idle and suggested I take some fuel out to get my AFRs to stoich at idle. I loaded up Logworks2 and found out my idle AFRs were 16-20! Yes I was running lean. So today I started to think and wonder if the fireball from the beginning of this story could have messed with the wideband's calibration. I re-calibrated it and BAM my idle AFR is stoich again. I took the car out and did about 15 min of realtime datalogging and it showed that I was 11ish at WOT, 20ish at no throttle and 14-15 at cruise/idle. Perfect AFAIK. I just tried to go out to the movies and got another CEL Another trip to Autozone shows yet another pair of P0172s. I'm completely lost now. Could the primary O2 sensor have gotten fried by the fireball? Ideas?

 

Oh yeah mods, which are in the registry:

XEDE+SMART
272/264 cams
Vishnu 3" TBE
UR 3" cat
White Rabbit
Denso 660s
Forge (recirc) DV

I just thought of something, could the clicking that I think is coming from the XEDE actually be from the injectors?

 

P0172 from what I understand is you use CEL fix for it. Maybe your ground on your cel fix on the Xede came loose, check that. I think I got that code before because I had to CEL fix's on the car, one for the Xede and second on from Perrin.

 

All the XEDE's grounds are fine and there's no CEL fix builtin AFAIK.

 

The clicking that I thought is coming from the XEDE is coming from the passenger-side of the car, which I think rules out the IAC solenoid. I'm really hoping the ECU isn't freaking out and causing the fuel system to keep changing from closed to open loop.

 

bump

 

All closed loop conditions are controlled by the front o2, which is unrelated to the cel fix. A bad o2 sensor generally pegs, in one dirrection or another, which would certainly cause these issues you are running into. Either way you are seeing upwards of a 20% correction in long term closed loop fuel trims. Since the code came back, I would try swaping your front o2 with another local guy to see if that fixes the issue.