First let me begin by saying I have found this forum a treasure trove and the members a helpful and knowledgeable community. It is my first post here, and I am confident the members here will be able to help me!

I bought a modified 996 Turbo in 2012, with 40k miles on it (larger throttle bodies, larger KKK turbos, modified Y pipe blow through MAF, EVO airbox) Over the last year and half have put on 4k miles.

Few hundred miles ago, the CEL came on intermittently. Reset CL, put Techtron...changed the oil. Felt a hesitation around 3k RPM. No performance issues other than that. Reset lights, seemed to be ok.

Drove the car 70 miles, misfires above 3k RPM. I had my garage change the spark plugs, clutch, coil packs.

I drove the car about 50 miles, no issues. Then CEL came back, this time with bigger and more frequent misfires. Car went into limp home mode. Occasionally could see unburnt fuel.

Took her back, shop had my car for 4 months, finally said all misfires were specific to one bank. Changed the solenoid bracket and sensor/actuator (which is what I told them to do in first place).... and now they say that the ABS/PSM light is on...Ordered a new MAF (not the OEM, I have a custom blow through...think it is a For MAF)....light is still on.

The shop has now given up....say they can't "fix" the issue because it is too heavily modified to know what exactly is wrong.

the shop has been great in terms of trying their best/good intentions...but I cannot believe that this is such an unfixable issue!

They say the car drives fine now, other than the lights....but I have a feeling that this is just temporary.

I have asked if they performed a vacuum leak test, they said yes. The owner's son who seems unfamiliar and wary of mods (did not know what my MAF set up was) says it "could be a twisted camshaft"?? Am less confident he knows what he is talking about.

Any suggestions? Please Help!! I'm already out significant $$$ and no solution.

 

you cant have both a blow thru maf and a evom airbox at the same time... so I think you have your facts wrong as well... if its not like this one below then you dont have a blow thru...
so you ordering a new maf doesnt make sense at all... Im guessing you have a oem maf or the hitachi one if you have the airbox...



Uploaded with ImageShack.usma

 

Thanks for getting back to me. I will post a picture of what I have, but I understand what you are saying...and no, it doesn't look like that to me.

I will take a picture of the old MAF but according to the mechanic it was a BOSCH unit but not the Porsche OEM...and not a Hitachi...was just quoting what he said. He claimed it was used in GM cars....

So it doesn't look like yours...and he did order a new MAF. I will get the error codes from him.

The interesting thing is that I had no ABS/PSM failure prior to taking the car in....just the CEL. It was after they changed the solenoid/actuator & bracket that this came on. They ordered a new MAF in hopes of clearing it...but that didn't work either. Not sure if the two incidents are connected...but wanted to disclose in case it helped.

Thanks again.

 

sounds like a problem i very recently had

change the n75 valve, boost pressure sensor, and make sure every clamp on ur after market y pipe is really really tight especially the one that attaches to the F hose

 

start with a new OEM MAF assuming your tune is for an oem maf and not for a Hitachi for example... then do a pressure test .

 

Thanks Tim and Markski.

I know that I have a REVO flash on it with 3 settings to choose from and that when this car was being tuned, this "custom MAF" was set up( personally, I would have preferred to remain OEM, but that is neither here nor there).

I know it is not a Hitachi unit...I really need to get back to this board as to what the hell type of MAF I have in there (am traveling and will be back in 2 days, so will get back to forum when I pick her up)...and whether I can simply switch from one Bosch unit back to the OEM Bosch unit. I know whatever the current set up is...it worked for a few thousand miles (and assume the 40k miles before)...but happy to try anything at this point that isn't cost prohibitive.

If it is MAF related, would driving it with MAF disconnected for a bit help pinpoint the problem?

Makes sense to do a pressure test, tighten clamps etc. Even change n75 if that does not work.

I had asked the shop whether it made sense to just go back to stock MAF + intake config and they said it is cost prohibitive to do so as I didn't have any stock parts. Is it really that expensive?

Either way, it is time to take it to a new shop as this shop self-admittedly is not familiar with modified turbos as much as stock. Any recommendations in the NY/NJ area that is very familiar with boosted 996TTs and will know what to look for?

I searched the forum and hear good things about RPM and TKX. A friend recommended JSS Performance, though online reviews are limited.

Thanks much guys.

 

Your complicating things.
Take some pics. Of the Maf. Your engine bay.
I think someone is is giving you misguided info.
This is easy. Revo does not tune for after market mafs.
I suggest getting rid of it. put in a good tune and a new Maf. I bet your problems work go away.
Until then good luck.

Markski

ps. how to test for a bad maf( or at least have an idea if its good).. while the car is running disconnect the harness form it and see if the rpms blip a little... ( exhaust changed a note)... if so, the maf is still working... if not its probably shot.. now, you may have some cheap ebay one as well... OR, the tune is not right and the maf is blowing up... etc...
this is easy...

 

Its your MAF replace it.......

 

You guys are awesome. I emailed the shop weeks ago before they put it in for the MAF....and he said "I don't have a part number.... it's discontinued and Bosch doesn't make them anymore". He gave me this number 03-09-02-1c s.

I am going to ask him again as the part has arrived and he's installed it.

Guys, especially Markski, I know how it tries one patience to explain obvious stuff to a newbie...so really appreciate that walk through. This sh*t has been going on for 6 months....and I get answers like "it might be a twisted camshaft... "

I will take a picture and post in a few days of engine bay and MAF.

 

Lol u think this is bad lol you have no idea. This just a little issue.

 

there is apparently more to driving fast cars than living life 'one quarter-mile at a time'.

 

Sounds ominous 996TT550! I hope it is a little issue...

Got some info about my MAF:

The MAF that was in, and which they replaced with a new one of the same is a Bosch Unit # 0261230042. The link below shows that it is "compatible" with my car....

They tried fitting a regular MAF but said it did not fit because of the custom MAF/Y pipe set up...so they reordered a new unit of what was already in there.


http://www.oreillyauto.com/site/c/de...2203&ppt=C0033

 

Thats not a MAF thats a MAP sensor you need to get a new mechanic lol. Your MAF sensor is by the air intake. MAP sensors dont go easily.

 

I thought MAF and MAPs, while different, essentially achieved the same end?


The shop says I don't have the traditional MAF set up, I have a MAP instead.

From the DIY videos here, I can see where the MAF is supposed to be, I'll check my car...but does the 996TT have both a MAP & MAF....I thought it was usually one or the other...and that MAP was a possible way to go for high boosted cars?

 

Post a pic of your setup. MAP sensor do not go on our cars unless you have oil going through your boost hoses. Something is not right if you dont have a MAF then you have a maffless setup.