Hello,
I have recently rebuilt my engine and am having an issue with my AFR. The A side runs around 13-15 AFR except during WOT. The B side is consistently 0.5-1.0 AFR higher than A side during the first 10 minutes of driving, but after those 10 minutes the B side of the exhaust is reading 15-19 in gear and up to 20 AFR during idle. Also after the 10 minutes of driving, there is popping in the exhaust especially during times where I am pushing on the clutch or have the car in gear without pushing on the gas pedal. This only happens on the B side.
I have tried:
Check for exhaust leaks - there was one but it only improved the AFR by about 1
Checked vacuum hoses - all are connected and are new silicone hoses
Swapped the A & B wires connecting O2 to the gauge - no effect
Replaced the wide band sensors - no effect
No smoke except a small puff on startup
Visual inspection shows that both mufflers have turned yellow/gold and have spots that are blue/purple, but the rest of the exhaust is higher quality and is unchanged
Codes:
P0150 (pending) - O2 sensor circuit (bank 2 sensor 1)
P2198 (pending) - O2 sensor signal biased/stuck rich (bank 2 sensor 1)
--there was another code that I saw once for lean but never saw it again--
There are usually no codes but sometimes one or both of these two appear. They are very inconsistent appearing at random times. Sometimes one code appears but other times both appear and they never become "confirmed." If I clear them they don't appear until sometime after the engine starts having high afr/backfires
I've tried researching my specific situation but I cannot find any information on this exact problem.
Any insight would be appreciated, thanks.
Relevant parts:
ENGINE: 331 w/ dart block, edelbrock intake, afr 205 heads, scat 331 rotating assembly, 70mm accufab TB, Anderson CAI, 75mm Pro-M MAF, Pro-M ECU OBD-II, 30# bosch injectors, bbk fuel rail, stock fuel pressure regulator, silicone vacuum lines, 255 lph fuel pump, canton oil pan w/ pump, Smog delete, MAP delete
EXHAUST: BBK shorty headers, BBK cat H pipe, Walker quiet flow muffler
AFR: DLG-1 dual lambda AFR gauge, Bosch wide band sensors
I have recently rebuilt my engine and am having an issue with my AFR. The A side runs around 13-15 AFR except during WOT. The B side is consistently 0.5-1.0 AFR higher than A side during the first 10 minutes of driving, but after those 10 minutes the B side of the exhaust is reading 15-19 in gear and up to 20 AFR during idle. Also after the 10 minutes of driving, there is popping in the exhaust especially during times where I am pushing on the clutch or have the car in gear without pushing on the gas pedal. This only happens on the B side.
I have tried:
Check for exhaust leaks - there was one but it only improved the AFR by about 1
Checked vacuum hoses - all are connected and are new silicone hoses
Swapped the A & B wires connecting O2 to the gauge - no effect
Replaced the wide band sensors - no effect
No smoke except a small puff on startup
Visual inspection shows that both mufflers have turned yellow/gold and have spots that are blue/purple, but the rest of the exhaust is higher quality and is unchanged
Codes:
P0150 (pending) - O2 sensor circuit (bank 2 sensor 1)
P2198 (pending) - O2 sensor signal biased/stuck rich (bank 2 sensor 1)
--there was another code that I saw once for lean but never saw it again--
There are usually no codes but sometimes one or both of these two appear. They are very inconsistent appearing at random times. Sometimes one code appears but other times both appear and they never become "confirmed." If I clear them they don't appear until sometime after the engine starts having high afr/backfires
I've tried researching my specific situation but I cannot find any information on this exact problem.
Any insight would be appreciated, thanks.
Relevant parts:
ENGINE: 331 w/ dart block, edelbrock intake, afr 205 heads, scat 331 rotating assembly, 70mm accufab TB, Anderson CAI, 75mm Pro-M MAF, Pro-M ECU OBD-II, 30# bosch injectors, bbk fuel rail, stock fuel pressure regulator, silicone vacuum lines, 255 lph fuel pump, canton oil pan w/ pump, Smog delete, MAP delete
EXHAUST: BBK shorty headers, BBK cat H pipe, Walker quiet flow muffler
AFR: DLG-1 dual lambda AFR gauge, Bosch wide band sensors