More Error Codes ~ The Saga Continues

[Alynn]

After replacing the IAC and the Ignition Switch, our loss of power seemed resolved and I was left with a P0420 code only. I have been researching and trying to determine the best course of action....

Tonight, we took Pixie for a spin, and all of a sudden we had intermittent loss of power PLUS the tachometer and the speedometer stopped working. Limped along to Autozone to have codes read. Here is the list, plus what I think my next steps should be.....

P0420 Catalyst System Low Efficiency
P0032 HO2S Heater Circuit High Voltage Bank 1 Sensor 1
P0038 HO2S Heater Circuit High Voltage Bank 1 Sensor 2
P0501 Vehicle Speed Sensor Range/Performance
U0155 Lost Communication With Instrument Panel Cluster (IPC) Control Module
U110C NO FUEL LEVEL BUS MESSAGE
P0508 Idle Air Control Valve Sense Circuit Low Replaced IAC Last Saturday

What I think I should do:
Check for Vacuum leak - due to the fact that I just replaced the IAC with a brand new one.
Replace both O2 sensors
Replace VSS
After that, I am at a loss with respect to the U0155 and the U110C Does any one have any ideas, and am I on the right track so far? Does it sound like I have a bad instrument cluster?

Boy, this is crazy. I seem to get one code/problem clear and then -wham- more codes/problems crop up.

I do have to say that I understand that I bought a 10 year old car, and to be honest, we only paid 2,300.00 for it. I knew there were going to be things to fix. I am not a mechanic, however, I am mechanically inclined and not afraid to try to figure things out.

I had planned to replace the plugs and wires this weekend, but I think I have bigger issues to deal with first. We really love this car and I want to get it running in tip top (and especially SAFE) condition myself if at all possible.

I love having this forum to come to. You all have been very helpful, so far and I expect nothing less for the rest of my PT adventure.

I'm sorry that this post is long, but I hope that it has been fairly readable and understandable.

Thank you again for all of your help and understanding!!!

Alynn

[ptcruisersteve]

I would suggest checking your battery. Have a battery load test done. If the voltage gets low enough it can give you different error codes.
Check the battery cables. Make sure you are getting good contacts.

You probably have at least two problems.

One is your catalytic converter might be clogged or not working properly. How long does it last before the P0420 error comes back on?

On the other error codes I feel you might have a weak ground somewhere. Check the ground for the Instrument Cluster. Check your ground wires under the hood.

[JoeX]

Originally Posted by ptcruisersteve

I would suggest checking your battery. Have a battery load test done. If the voltage gets low enough it can give you different error codes.
Check the battery cables. Make sure you are getting good contacts.

You probably have at least two problems.

One is your catalytic converter might be clogged or not working properly. How long does it last before the P0420 error comes back on?

On the other error codes I feel you might have a weak ground somewhere. Check the ground for the Instrument Cluster. Check your ground wires under the hood.

I agree with Steve, and want to add that checking the grounds is not just looking at them to see if they are attached, Copper (grounds) get dirty and the tarnish look is more or lesss their way of rusting. they need taken apart and cleaned, tinned with solder and then resoldered to the cleaned eyelet. That was what cured my o2 sensor circuit high code.

[Alynn]

Steve:

I had the battery checked at O'Reilly's about 2 weeks ago, right after the loss of power happened. I'm not sure they "load tested" it, but he did 'check' it and the meter/tool said that the battery was good.

It was about 100 miles before the CEL came back on from the last time I cleared the P0420 code last Saturday. I have read several places on the forum that the P0420 could possibly be caused by the 2 o2 sensors. Any thoughts on that train of thought? Also, if it is the catalytic converter, will it hurt the engine to run it with the code still keeping the CEL on?

I'm not too familiar with the electrical/wiring aspect of a car, but I am willing to learn. Could you explain the best way to check the ground wires?
I have a multi-meter if that is a useful tool for this purpose. I don't mean to sound dumb, but with cars, I kind of am..... But I want to learn to do as much as I am capable of, I just have to work the learning curve..

Thanks for taking the time to help!!

Alynn

[LionPT]

I would just worry about the U0155 code for now...than look into the P0420 code.
I too agree about the grounds...pay particular attention the the negative ground that goes from the battery to under the drivers fender.
Remove the air box & unhook the battery & remove it. Remove the ground from the fender & inspect it for a loose/broken connecter or wires...also make sure it is attached to bare metal & not rust.

[Alynn]

LionPT:

That sounds doable. I will be working on Pixie tomorrow and will report back.

I have had the battery disconnected (disconnecting the negative cable only) several times in the past 2 weeks, fixing problems, and clearing the codes. It is possible that I've disturbed the ground connection in some way.

Thanks, and I will let you all know what I find.
I am also going to do the vacuum leak test to see if I can find a leak, to clear up the P0508 code, as well.

Once these are cleared up, I will the work on replacing the O2 sensors and the VSS if those codes show back up.

One fix at a time to keep organized and not get overwhelmed. Also, from working with computers, you must not try more than one solution at a time, or you end up not knowing what the actual problem was, or which solution resolved the issue....


Alynn

[Alynn]

UPDATE!

I checked / cleaned the battery ground wire, no rust, no visible damage. I also replaced the ignition switch, as I had advice from rob342 that this could be part of the problem.

I did the vacuum leak test using carb cleaner, no revs, or change in the engine running at all.

We drove it about 12 miles yesterday and today, and the CEL comes back on. I did the "key dance" and only had the p0420 code show., so far.

One thing I missed from ptcruisersteve though, is checking the instrument cluster ground. Can you tell me where to find it? I am assuming it is behind the cluster, which involves removing the dash?

Thanks for keeping up!

Alynn

[ptcruisersteve]

I will get back to you on the location of the Instrument Cluster ground wire.

The link below seems to have the same approximate issues as yours did.

http://www.allpar.com/forums/threads...r-dies.151900/

[ptcruisersteve]

I am still looking for access to the ground wire. I have not found the thread that showed the ground wire. Maybe someone else knows.

[Alynn]

I appreciate it. I will be driving her to work today, kind of a test to see if changing the ignition switch cleared the problem. I drive 20 miles each way, so we'll see.

Have a Great Day!

Alynn