steveu812

'99 coupe 76 miles and more codes than a channel trolling U-boat.

A new Durametric tool is reading these codes:
P1602 - Supply voltage Open circuit
P0452 - Tank pressure sensor below limit (cap seal looked dry rotted new cap on order)
P0150 - O2 sensor ahead of cat conv Cyl (4-6)
P0130 - O2 sensor ahead of cat conv Cyl (1-3)
P0300 - Misfire damaging to cat converter
P0301 - Cylinder 1 misfile damaging to cat converter
P1319 - Misfire emissions irrelevant
P1313 - Cylinder 1 misfile emissions irrelevant
P0102 - Mass air flow sensor short circuit/open circuit

I just need to some help knowing where to start. Do I replace the plug on #1 and see if that clears that code or just replace that coil, or bite the bullet and replace them all with plugs? Is the MAF code mean there is a 90% chance it's bad so replace it? I suspect the MAF and misfire on only 1 cylinder indicates both a MAF and cylinder issue.

Thanks

Mark I

I would see how much benefit is to be had from cleaning the MAF before doing much else other than maybe inspecting or replacing #1 coil.

Imo000

I would start by swaping the coils between #1 and another easily acessible cylinder. If the missfire code follows the coil, its that coil that need replacing. If not, switch the spark plugs between cylinders and see what happens

steveu812

I was going to remove the MAF to clean it but I didn't have the correct T20 security torx so I removed the air box. It looked very clean inside but I have to ask if where the wire does a u-turn - is it supposed to look like this?

Macster

The few times I've viewed a MAF that is what that wire looks like.

BTW, the MAF is a hot film type and the working surface is inside that passageway that goes through the MAF.

The MAF as you found was not dirty. They never are.

My WAG is the MAF is bad.

You can clear the codes. Disconnect the MAF at the harness and drive the car and see if the symptoms return.

If the CEL comes on read (but do not clear just yet) the codes. If the code is related to the MAF being disconnected that's one thing. If the codes point to say a cam timing issue that's something else and your test drive is over. Turn off the engine and flat bed the car to a shop. It needs a pro's attention.

Or if the engine starts making noises, the above applies.

I do not believe this will happen I'm just being cautious.

Did you have the battery disconnected or have you had any problems with the battery?

It is a long shot prompted by the P1602 error but a bad battery or a bad alternator can cause all sorts of seemingly unrelated problems similar to what you are reporting as the electrical needs of the engine/car can not be met by the battery/alternator.

steveu812

I just got the car so I don't know if the battery was disco. recently. I plan on crawling under and swapping coil packs 1 & 2 tonight, but is it possible that the MAF would affect only one CP?

steveu812

Crawled under to swap coilpack 1 for 3. Removed the heat shield, barely pulled on the CP1 wire boot and it came off the coil. With the boot way down over the connector, it was hard to tell if it was engaging fully so I worked to get the boot high enough to expose the connector. I wasn't altogether successful with that but was able to mate the connectors with an audible click. The #3 wasn't much better so I reconnected that one. While I had the airbox off I removed the MAF and sprayed that down with CRC MAF cleaner. Reinstalled the airbox, hooked up the Durametric cable, cleared the codes and fired it up. It would barely idle at first but then seemed to get better as it warmed up. I took it for about a 5 mile test drive, running it up in the revs after warm and it never missed a beat. I'm in disbelief that it could be this simple (my last kraut car was a '96 Audi A4 that had more problems than a calculus textbook). I'm keeping my fingers crossed.

Thanks for the advice.

Macster

Good work. I was remiss in not suggesting you check the coils -- when one hears hoof beats suspect horses not zebras -- and with the misfire coils.. well, I should have suggested you look at coils, at least the one at the cylinder with the misfire.

lordsinclair

A year ago my '97 Boxster 2.5 engine cut out completely whilst I was driving, I got towed home, did the research, pulled the MAF sensor and cleaned it and it fired straight up and lasted...

Imo000

Stop throwing a bunch of possible scenarios hoping that one would stick. This is extremely confusing for those that are looking for good advise.