goodhart

iTrader: (3)

Ok, so this all started about a week ago when I decided to trim ~1/2" off of my Injen intake so that when I put my new Perrin filter on, it would not rub on the ACD reservoir like the old one had been. When I had bought the car, The previous tuner said he had to spend some time scaling in the MAF to work with this intake. (Can the MAF scaling change itself?) (I had it tuned for E85 by another shop in the spring, but I am pretty sure he didn't mess with the MAF scaling, he really had no reason to.)

Well, after cutting the intake, it ran fine for about 50 or so miles until it threw a CEL. I didn't really get into the throttle again until the next day and the car seemed like it had a massive boost leak and it still had a CEL. I cleaned the MAF with some MAF cleaner, that did nothing. I assumed I had a boost leak until I decided to swing by VatoZone in St. Cloud and scan the car for the codes. What happened next was a bit....overwhelming. LOL

Here is what came up:

1) P0401 EGR flow blah blah
2) P0113 IAT high input
3) P0102 MAF flow circuit low input
4) P2228 Baro pressure circuit low
5&6) P0171 System too lean (Bank 1) (I had 2 of these codes)
7) P0134 no activity detected (bank 1, sensor 1)

So, I found that the EGR line had popped off, put that back on and zip tied it again, and cleaned the MAF once more. Then cleared the codes and went home.

The next day I went back to the same store, used the same scanner after driving to work and back that day, and all that came up was the 2x P0171's.

At this point I figured it had to be the intake, as that was the only thing that had changed in the setup. I decided to track down a stock intake, and check on the MAF scaling, etc.

Friday: I picked up a stock intake and put it on the car. Since he had an 03 and I have an 06, the bottom section of the UICP did not line up (03-04 are the same bracket, they have the IC sprayer. 05-06 are the different because they have ACD in that location).

Saturday: I put this intake on, plugged the recirc, put my Injen UICP back on along with my stock BOV (My synapse did not fit with this configuration of piping) and hooked it up to vent to atmosphere temporarily until I could check the MAF scaling. (Which I thought was my problem originally, as a result of cutting part of the intake tube off). The car still ran like crap, but I hadn't had a chance to check on the MAF scaling properties yet, so I kind of figured it would.

Today (Monday):

I got a few stock ROM's from Kracka to compare my MAF scaling to. Sweet. So I drove up to a friend's place to plug the car into his laptop. When I got there, we ran EvoScan to check the codes again quick and got the following:

• 2x P0171's (system to lean)
• P2228 Baro pressure circuit low
• P0113 IAT high input

We then pulled up my "Airflow/Hz Raw Scaling" table in EcuFlash. We found this to be exactly the same as the stock IX ROM. WTF. So if it wasn't the MAF scaling, what was it? We looked at every MAF related table in the entire ECU and it all matched perfectly with the stock ROM. Now I am really confused. Could this mean the MAF is bad?

Symptoms:
• Running very rich at partial throttle (9.5-10.:1 AFR's)
• Running very lean when I can go WOT (Which isn't more than a second or so, and it is hitting 14-15:1 AFR's)
•Cruising AFR's are ~14.5ish
• Anything over ~4,500 rpm and/or ~10psi and it will shudder and miss like it has a boost leak, but the coupler hasn't quite popped off yet.

Possibilities?
• Bad MAF?
• Front o2 sensor?
•clogged injector?

What changed:
• trimmed 1/2" off Injen intake, then swapped it out for a stock one = No change
•Cleaned MAF = no change


*I have not done a boost leak yet due to the holiday weekend, but it is on my "to-do" list.

xRoguex

iTrader: (15)

sounds like your mas or o2 is crapping out..

IwantURevo

are your voltages correct? do you have an intake leak after the maf? our shop chased a smilar problem and ended up taping all the joints on the intake because it was leaking so badly after the maf. after that the car ran great.

190hpkilla

iTrader: (19)

Sounds like a vacuum leak. Check that first

goodhart

iTrader: (3)

Put a stock intake back on the car and it still ran like crap. 2 days and about 50 miles later? CEL went out and it ran perfect. Weird. I'm thinking it must have had to re-learn the new intake? I don't know, I don't care, it works now. haha

p.s. I hooked the battery AND cleared the codes in EvoScan before starting the car after the stock intake install.