doclingenfelter

This is my first post and want to thank all of you for getting me to this point. I finally worked out several problems that have been plaguing me for years. I was only able to figure out all of my problems by searching these forums. However, now I see seemingly random misfires (several from cylinder 2) popping up on my Diablosport Predator. There are neither codes, nor symptoms of the misfires. I have been running lean, but after some serious maintenance and some tuning from my device I have cured all codes except for a P1153. It popped up again tonight after my last tune. I adjusted my Injector slope from -10 to -12. At -10 my LTFT were steady between -0.78 to 0.00, but the P1153 (Bank 2 shifted lean) popped back up. On my way home I adjusted my INJ slope to -12 and the LTFT at cruise (1300 - 1800 RPM) shifted down to around -5.00 ish. On any acceleration the trims level out to 0.00. The code has not returned, however, the occasional misfire hangs around. Are these normal occurrences or do I have a problem? There is no stutter or hesitation. Thank you for any help or advice.

Russ K

iTrader: (1)

What mods? As LT headers will cause a P1153 (insufficient switching B2 S1) Nothing to do with a lean code. With LT headers, I set the insufficient & slow response codes for both banks to no error reported. Do you have an aftermarket camshaft? If so, it will set a misfire code and will need the idle & low RPM misfire event tables raised or maxed.

Russ Kemp

doclingenfelter

Mods are aftermarket lid, 85mm MAF, 85mm throttle body, lt headers with true dual. Other mods are wiring upgrades and whatnot. No heads or cam that I know of. The P1153 read "Bank 2 shifted to lean" on my diablosport predator, so just assumed it had something to do with my AFR. At the moment I do not have the means to tune them out and don't feel like paying the ridiculous prices that tuners charge here in NC. I could just buy HP Tuners for the price they seem to want to open their computers for. The misfires do not throw codes. I just see one or two on my data logged trips. Don't know if I need to address them or not since there are no symptoms of them.

Russ K

iTrader: (1)

Your Diablo code description is incorrect. Seen misfire counts on stock engines before with no side effects. Yes, you need HP Tuners to disable your O2 codes due to your headers. As a rule, the fueling will go open loop when any O2 code is current.

Russ Kemp

doclingenfelter

Sounds good. Good to know that it's probably not a problem. As a second option to the code problem, I looked up the heat reflection capability differences of coated headers versus header wrap and it seems that the wraps would hold in more heat than my coated headers. If that is the case, would wrap help bring the o2 sensors up to the desired temperatures?

Russ K

iTrader: (1)

Your O2 code is NOT caused by lack of heat. It's caused by the exhaust flow characteristics of LT headers. Header wrap will overheat & crack the headers.

Russ Kemp

doclingenfelter

Well crud. Well thank you for your help. I'll see if I can find a guy here that can help me out with removing the code. Seems like my only option.