OBD Code question....a very dumb question.

[oldmako]

Well the old gal is running like an old gal. So today I tossed in the three new coils I had in storage. It ran a lil mo betta, but not mo betta enough. So I pulled the new coils off the left side of the engine and placed them on the right. It ran better when the new coils were on the left, but not perfect. I just figured that I needed more coils. I then plugged in the OBD and noticed the following codes.

Fault 06 Pend 02

p0400 01/08 EGR FLow malfunction

p0325 02/08 Knock sens 1 circuit malfunction bank 1 or 1 sensor

p0300 03/08 Random / Multiple Cylinder Misfire

p0161 04/08 02 Sensor Heat Circuit Malfunction Bank 2 Sensor 2

p0330 05/08 Knock sens 2 Circuit Malfunction Bank 2

p0160 06/08 02 Sensor CKT No Activity Bank 2 Sensor 2

A few questions:

1. What are the number following the code? IE 01/08??
2. Why does the car idle fairly well when cold only to run lousy once its warmed up?
3. Why does the car run fine at highway speed (once it has been attained) but run like crap at the stop light and when accelerating? I would think that the knock sensor fault would cause the car to run lousy when accelerating as opposed to a no load situation IE traffic light.
4. I have read that failed Knock Sensors DO NOT cause the car to idle rough. All articles point to the coils. Obviously I'd rather spend the coin on more coils and leave the intake manifold alone. That KS job looks like a ton of dollar signs to me because at 197K and 13 years old half of the stuff will break during the removal of the intake.

This is the first time I have checked the codes in a LONG time. I cleared them out and drove the car and re tested it. It showed NO CODES but it still ran like crap. What gives? Were they ancient codes?

Confused if I should buy the rest of the coils or change the KS. The car has 198000. I THINK the KS were done at around 100K but I don't know for sure.

I've put about 90,000 miles on it since purchase and it has run like a string trimmer for 89000. Bummed, confused and slightly stoopit.

[Q451990]

I'd go coils first... then knock sensors if the code comes back, or they don't ohm test ok.

Heath

[Lokim]

The numbers (01/08) Are indicating which code of the total number of codes you are looking at, i.e. 1 of 8, 2 of 8, etc. If your O2 sensor heaters have gone tits-up, the car will run good cold because the car stays in open-loop, but runs like doo-doo warm because the 02's are sending inaccurate mixture info to your ECU. I would do 02 sensors (all of them) first.

[oldmako]

Those mothers are 50-235 each. So if I go that route I'll start with Bank 2, Sensor 2. According to IOS its the aft one on the pax side.

I see them labeled as Upstream and Downstream and Upper and Lower. My guess is upstream is in front of the cat and down aft of the cat. Sound right? Same with upper and lower??

So....would Bank 2 Sensor 2 be the right hand side, downstream sensor?? According to the FSM, it looks like the one right next to the trans fluid pan. Which would make it the upper.

Confused as usual.


So, it needs 4 coils and one $200+ sensor. According to my math, the car is starting to look like a liability given that the air is out. Last year a recharge held it for most of the summer but leaked out.

FSM says to check the engine grounds first and harness integrity / continuity. I'll do that first and keep my fingers crossed. Then I'll toss a sensor in if necessary.

Were it not for the new seats, 4 new coils and Michelins, I might just push it off a cliff! hahahahah

[maxnix]

In reality, you need all new coils. I tried substituting them in as they failed and it was a dog chasing its tail.

You need to replace both knock sensors. This involves open heart surgery. But on your way in you will be able to clean the the EGR and IAC valves and unclog the EGR tube in the top plenum. I assure you it is clogged completely closed. Replace at least the bottom cooling hoses off the T to the heads. 2 KS and I would recommend harness. Be very careful removing the clips on the injectors as they are brittle and brake and unlike the VH45DE, you have to buy the whole EGI harness to replace them.

Check my post for where to send your injectors for cleaning. You will need all gaskets (3 on the EGR alone), and it will be an excellent time to replace plugs and valve cover gaskets, and of course new coil packs. It will run until you die then you can be buried in it, assuming you have maintained the PS, brake and differential fluids.

The Church of the Holy Plenum Job will take your calls 24 hrs. a day. Arise and go forth and smite the carbon build-up!

If you don't, your car will be like your avatar, dead.

[oldmako]

Just to update....

Today I installed 4 coils from the 8 that were advertised here about a month ago (Feb 2012).

I had 4 decent ones that I had purchased earlier at a close out price. One had about 40K on it and the others were new. The car still ran like crap with 4 new and 4 old. I tried moving them about to isolate the mofo and had no luck.

The car now runs perfectly. My Q-Bomb is back and I am smiling. I didn't mess with the O2 sensors, sensor harness or Knock sensors. I'm a big believer of doing the easy stuff first and then pouring a cocktail if the results are satisfactory. I didn't take the plenum off and I didn't bust anything. I spent 45 minutes under the hood then changed the oil and added freon. I am now enjoying a cocktail. Tomorrow I will ask the car to propel me at a great rate of speed down the interstate.

[maxnix]

The car still ran like crap with 4 new and 4 old. I tried moving them about to isolate the mofo and had no luck.

So how did you "fix" it, or did the cocktail just make it seem better? You may not want to do the hard work, but that doesn't mean it doesn't need to be done.

[oldmako]

Three of the coils are brand new. One has approx 40,000 and the other three which were removed from a wreck have 53,000.

The car now runs perfectly and the four original coils were the culprit. Not the KS, not the o2 sensors. Why those codes were present I don't know. If there is something wrong with them, it doesn't seem to affect the performance of the engine or gas mileage. The car now runs just as it did when I bought it 100,000 miles ago.

I have read several posts on this forum from guys who caused for more trouble than they solved when they removed the intake.

The car has 200K and is worth $1900 according to Edmunds. It is not a collectible. I'll take "reasonable" care of it until the trans goes out or some other hideously expensive repair but I won't break the bank or my back to keep it on the road. Seems to me the "plenum job" is north of $1000. Why bother when the car runs great (and I don't have a garage and I do have a 53 year old back)?