Intermittant P0219a and P0119f
 

Engine just rebuilt after damage from rocker arm ejection. Before the rebuild, the engine backfired and destroyed the air box. Injectors were professionally cleaned. Checked for vacuum leaks with starter fluid. Retorqued exhaust. Engine runs good. Codes pop up every 4-5 drive cycles. Any ideas out there?

Are there other parameters that I should log? At this point, even sarcastic comments would be appreciated.

Ok log appears to show there is fueling problem


High positive fuel trims and also the commanded afr is way leaner than actual afr, and commanded afr seems lean


ill answer your PM

What mods and tune do you have on the car? Hopefully you have replaced a stock airbox and not CAI

should log your PI Ratio and also close loop fuel system status. Will tell you if on PI or DI this happens and if its in close loop or the trim is applied blindly at open loop due to previous learning. I see that that STFT and LTFT are sometimes opposite and canceling each other out so maybe you need more drive cycles in close loop

Yes. Replaced with stock airbox. The car was dyno tuned a couple of years ago after installing a catted header and aftermarket over pipe. All was good until it went south. I'll log PI and closed loop status. I forgot the oversize valves. I had originally planned to go FI but probably won't.

A friend is helping me with data logging using Torque app. He couldn't find a way to log PI ratio. What should we look for? I'm on my 3rd tank of gas and get 21 mpg with my commute to/from work. My code reader says closed loop but we can't find that on the Torque app either.


I'm really wondering if the maf was damaged with the backfire. What specific parameters should we look at if the maf is giving the ceu bad numbers but not bad enough to set a code?

Check your O2 voltage as well as your MAF voltage at cruise and idle. You can pickup both at a salvage yard for pretty cheap and just replace them anyways as a precaution. You can inspect the MAF do closeups is the outside and 2 inside resistors if you have a decent camera.

Are you stock, what mods?

Thanks



I can check the voltages but I don't know what I'm looking for. I'm trying to avoid just throwing parts at it but it may come to that.

Mod list: Afe catted header, aftermarket over pipe, borla axleback, Perrin drop in filter Element Tuning big valve heads. Everything was fine with these mods before the rebuild.

You need to compare your values at idle, cruise, WOT pull with another car that's close to yours if you have MAF scaling changes / tunes. or look at abnormal jumps / changes without any inputs.

How did the airbox get destroyed but the MAF sensor is intact? again do more close visual/camera/ microscope examinations of it for damage

I just ordered a used maf off of ebay. It's off an 18 with 23k.

New/used MAF came on Saturday. I cleaned and installed it, drove the car around Sat and sun, CEL came on on my way into work this morning. P0219a, P0119f and now P0304. Later this week, I'll datalog again.

No solution yet. I sent my datalog to my tuner but even after reminder calls and messages he hasn't gotten to it yet. I did another datalog session but there was no change with the "new" MAF. I made a smoke machine but found NO leaks.



https://datazap.me/u/blsfrs/thanksgi...g=0&data=10-22


I appreciate the help that I've gotten so far. Any addition input out there?

Your LTFT improved actually assuming you were driving around the same way. They're much tighter +/- 5% so you improved some things. Next you need to examine your O2 sensor and dive into debugging. There should be tons of material on youtube/google on how to do it