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View Full Version : 557P ECU in a 99.5 1.8T misfires...



AustinQuattro
03-14-2009, 07:38 PM
I took the 559C out and put in a 557P that was APR chipped, and it is so much better...but it misfires when getting on it...is there any recoding that I need to do with the VAG? Maybe I've just got a dirty fuel filter or my coils are acting up. The plugs are new Denso Iridium plugs. Anyone have any ideas?

Basically, the ECU is from an older B5 with the AEB engine, but the one that came out of my 99.5 was 559C and the one in there now is a 557P...[wrench]

acollicott
03-14-2009, 09:24 PM
Try gaping the spark plugs down to 0.028

Jibberific
03-15-2009, 12:44 AM
well that makes sense, because 557P is what is supposed to be in a 99.5

AustinQuattro
03-15-2009, 07:29 AM
I'm not sure how that makes any sense at all...the car was OEM stock with the 559C in it, and I bought the 557P from someone with an APR flash on it. And it works great, except that there's the occasional missing. The spark plugs are pre-gapped. I may try the spark plug regapping, but my biggest question is this: do I need to recode anything when I put the 557P ECU in the car? It seems like maybe the timing is a little bit too advanced (there was pinging).

black99.5a4
03-15-2009, 07:35 AM
I'm not sure how that makes any sense at all...the car was OEM stock with the 559C in it, and I bought the 557P from someone with an APR flash on it. And it works great, except that there's the occasional missing. The spark plugs are pre-gapped. I may try the spark plug regapping, but my biggest question is this: do I need to recode anything when I put the 557P ECU in the car? It seems like maybe the timing is a little bit too advanced (there was pinging).


the fact that your car is chipped now, you might of exploited a bad coil pack and now its acting up on you. Get it scanned or find someone with vagcom. if you goto autozone and it says random misfire cylinder 3.. move a coil pack from another spot to the 3 cylinder, see if the misfire follows where you stuck the coil.. if you stick 3 in 1 and get a random misfire 1.. then its the coil pack.

if it comes up and says random misfire cylinder 2, you move the pack and it still says 2, it could be the ICM.

Also, are you running at least 91 octane gas?

AustinQuattro
03-15-2009, 07:38 AM
I have a VAG-COM and ran it the other day but it wasn't doing it...I'm going to run it today and check those things. I'm running 93 octane. My wife did put some 89 in there, and I sort of freaked out a bit, but unless you're getting into it, it doesn't matter that much anyhow. I've since cycled enough 93 through that there should be no issue.

I'll check the coil packs today.

acollicott
03-15-2009, 09:20 AM
That's exactly what mine was doing after I got chipped, i put 'pre-gapped' spark plugs in there only to find out that they weren't gaped right and when i got on it, it would blow out the spark.

But it might also be the coil packs, they have tendency to suck. Both are really easy to check though so do that before you buy anything

akielb
03-15-2009, 09:47 AM
well that makes sense, because 557P is what is supposed to be in a 99.5

All AEB ECU's are interchangeable.

bass_lover1
03-15-2009, 01:04 PM
Are the Denso plugs triple electrode or single? If they're single, you're using the incorrect plug for an AEB motor.