02 Boxster engine misfires, stalls, and shuts off! help !
 

"PROBLEM FIXED" Hello my friends, as I stated on the tile I am having major problems with my 02 boxster, it is a base model with 160k miles, de-snorkled, and K&N filter(installed 90 miles ago) Here is the whole story:
A few weeks ago the after I installed the K&N the car started stalling and it would shut off by itself, I took the MAF out and cleaned it with MAF cleaner which worked great because the car stopped shaking. A week later the car felt slower so I hit the gas to see if I felt a huge difference in power and about 6800 rpm the engine completely stalled and all the pilots appeared on the dash but disappeared in a few seconds. After that, the engine was shaking and stalling like crazy, when I hit the gas it would start to backfire through the intake and then it would just shut off. I tried cleaning the maf again but with no luck. The car does the same thing everytime and it is imposible to rev it over 2k rmp without the car shutting itself after a few intake backfires. The car doesn't has the "check engine" or cel light on. I disconnected the MAF then started the car and it runs the exact same way as with the MAF connected, there was no noticeable difference and it would still misfire, stall, and shut off.
My question is, if the MAF failed, would the CEL light come on? could the MAF be the cause of the engine misfire and the intake backfire?
I also read that it could be the coil pack, fuel filter, an intake leak, timing chain tensioner failure, or the timing being way off.

If you guys have any guidance to narrow my search it would be greatly appreciated, I was thinking on going ahead and buying a new MAF but the fact that the CEL hasn't come on makes me think that it might not be a MAF problem.
Thanks a lot for your time and have a great day !
Vinicio
p.s. (sorry for my english, I'm Italian and I'm still learning haha)

Quote " I installed a K&N and the engine started stalling ????HUH ??? DUH ??? Just shoot me.

Benvenuto Vinicio,

From what I've heard a K&N with any excess oil in it can foul the MAF. CEL or no CEL if disconnecting the MAF has no affect on how the engine runs, then there is an issue with the MAF.

actually, if you disconnect the maf the computer defaults to throttle position instead of airflow to establish fuel delivery and the engine should run fine. so, if the engine continues to behave poorly with the maf disconnected then it is not a problem with the maf. perhaps millimax deserves a duh right back at 'em. so, either the air filter change is just a bad coincidence with the engine problem, or you accidentally dropped something in the intake while doing the change - cheeseburger, small tonka truck, bag of bolivian marching powder ...

Ok I will shoot you :D Well to tell you the truth I didn't think all the stories about the k&n were true but right now I think It is a big possibility. It's just weird, I've been using k&n on my z4, my cobra, and my GT, and I've never had a problem with those. On the other hand, the engine is running so rough right now that is hard to believe it is just a faulty MAF, if you rev it close to 2k rmp it will back-fire and die, the car is not drivable right now, it won't move one meter without shutting off, it also seems like is becoming harder to start when I crank it. Anyways thanks for the input

thanks for your input my friend ! that's what I was hoping to hear, I did the same process today (starting the car and disconnecting the maf) and for about 3 seconds the car seems a little stable and then it goes to hell again, but the exact same thing happens once I plug the MAF back in, for about 3 sounds it calms down and then all the shaking and backfiring starts. Thanks again ! Ci vediamo !

I was very careful not to drop anything, while the maf was out I sealed the hole with tape just in case a squirell wanted to find a new hiding place haha what you say has a lot of logic, I'm going to try it again tomorrow and see if disconnecting the battery does something different, I just hope it is not the timing chain :S

I have an update, I disconnected the MAF again but this time I disconnected the battery to reset the ECU. There is a huge difference on how the car runs now, I was actually able to drive it and rev it passing 3k rmp without the car shutting off or the constant backfire(it did it a couple of times though) I bought the new MAF and should get to me by friday, I'll take the K&N filter out just in case, it is not worth the risk even though you can feel some performance gains. I'll let you guys know if it was the MAF the cause of my issues. Thanks everyone for your answers !

UPDATE" I installed the new MAF and I have the same issues, any idea what would be the next step to take ?

I don't recall you saying this specifically, but what codes is your car showing? You'll need to use a code reader that'll also read pending DTCs. If you didn't have the codes read, perhaps that should have been the first step.

However, not all problems will store a code. But at least, with a code, we can help you narrow down the problem.

PROBLEM FIXED" I took the TB and plenum out and i found a cigarette bud stuck on the TB'S butterfly. The TB was open all the time and that simulated a huge vacuum leak that made the engine run lean. Cleaned everything out and it runs very good now. thanks everyone for your help !

A cigarette butt ???? Did I really read this ??? How in the hell did a "butt" get in the system ???? I think I know but want to hear from you all. Have not had my first Martini....YET.

and the winner is ... ME!

You da King !!! Marching powder ? Huh ?? Ya think ? You da King !!!!!!!!!!!!

It's likely that the cigarette butt was sitting on the filter when he pulled the old one out. It dropped down into the housing in the area below the filter, where the intake is. There should be a small screen on the intake to keep the big objects out, but it could have slipped past.

I always check for debris when I pull the filter out, and run a vacuum around the housing.

+1

Stick the good old shop vac down there and you'll hear it sucking little sticks and leaves even with the filter out.