[tnhillbilly]

Hi, I just joined the forum and I want to thank you all in advance for any info you can give me on this code. I have a scanner that I just got a few days ago and I'm still learning on it. I know the code has to do with bank 1 low emissions efficiency. I tore the engine down a couple of months ago because I bought it with a blown head gasket. No signs out the exhaust, all the compression was going into the cooling system. Anyhow, after fixing several things besides the head gasket, when I put it in on the road it started throwing this code. It has been a day or two since I was under it, but I believe it only has 1 cat and I think 3 02 sensors. I watched the scanner when it was hooked up with the van running and all 3 02 sensors seemed to be acting alike. From what I can find out the one after the cat is supposed to kind of flatline and not bounce around on the voltage like the 2 before the cat. If I am right, this means the cat needs replacing. I am kind of an old school mechanic and grew up on cars with carbureators and distributors with points and condensors. SIGH !!! I wish I had my 57 Chevy's and my 66 Mustang back ( Sorry I know this is a GM site, but I have owned them all and I really liked the 50's and 60's cars when they knew what hotrods were). I have turned wrenches for 30 years but I'm not used to the newer vehicles. If anyone has had this code and knows what the fix is please let me know. It costs way too much to just start buying parts.
Thanks

 

[spongebob218]

If the O2 sensor after the cat is reading the same as before the cat, it means the convertor isn't working and needs replaced. If the O2 sensors were faulty there would be codes for them individually. If there are no other codes but the P0420, it means that the sensors are working the way they should. The sensors have to pass tests in the PCM before it runs the test for the P0420. Put a catalytic convertor on it. The bad head gasket is most likely killed the cat, of course it could have been the mileage also.

 

[tnhillbilly]

Thanks for the info. I guess a cat is next on the list as soon as I get the cash. The van runs fine but I will get the cat installed asap before it causes any more problems.

 

[2002Safari]

Is your cat rattling? Mind did but I didn't get any OBD codes however, I couldn't pass emission control for relicensing the van.

 

[tnhillbilly]

Hi, No it wasn't rattling. I did have a flashing engine light when I bought the van with a blown head gasket. I knew that was a sign of unburned fuel and converter damage occuring. I kind of figured the cat was toast but I wasn't sure. I am lucky though, we don't have an emissions test here yet but I can't stand a check engine light glowing. I got the cat installed today. When the shop cut the old one off there was nothing inside. No wonder I had a ses light glowing. Since I got the new one installed the van idles smoother and there is no engine light. Thanks for all of your input.

 

[ALPO]

This thread seems appropriate to my current disorders. On the way home tonight my van seemed to have lost power (hard to maintain 65 MPH without downshifting, and when downshitfted it seemed to even have less power) gas milage also dove down to ~13 MPG from a not so good but average 17.5 MPG. Milage did get better as speed (RPMs) decreased, I was back up to >15 at 50 MPH. I also seemed to hear ever so slight pinging from the exhaust. As the Check Engine Light was on I checked the codes as soon as I got home. There were two stored codes: P0101 (mass or volume air flow circuit range/performance) and P0420 (catalyst system efficiency below threshold (bank 1)) . This has me leaning toward a bad converter.

A Little History.

I have only had the van for a few months, but....., in that short time I had a problem with a bad coil and coil wire (not to mention a radiator leak, front wheel bearings, rear heater control valve,....blah, blah, blah - but the coil wires seems pertinant here). The bad coil and wire caused some occational misfiring and other various running problems including stalling and leaving me stranded at times. From what I read here these conditions can kill a Catalytic Converter. In that time I have also started hearing a "Rattle" coming from the Cat that also seemed to be getting slightly worse.

Years ago I remember driving a delivery car (ElCamino) when I was younger that had a bad Cat, power was EXTREMELY effected, more than this but I guess these things can go at different degrees. I believe in that case the Cat was clogged causing backpressure, but in my new case the P0101 code indicates no change in O2 levels through the Cat (also if I read this forum correctly). My Van is a 2001, used, and has 106K miles on her so any warranty is far gone (I have heard that Cat Warrantys actually last past the standards warrantys) and Cats are costly. FIRST, is there anything else that I should consider? SECOND, what are my options (cost!!!) for replacing the Cat?

Thanks, this forum has been great in diagnosing and assisting in repairing ALL my problems so far. Here's another roll of the dice.

 

[Stroverlander]

Been there, see this thread:

http://www.astrosafari.com/viewtopic.php?f=43&t=976

Interestingly, I still get the P0420 code occasionally but I am replacing all three 02 sensors this weekend as part of my major service. Also going to check for any exhaust leaks or pinholes in the cat welds.

 

[ALPO]

WOW! The first muffler shop quoted me a price of $1500 to replace both converters (they said both were bad). I quickly said NO WAY, I will pick it back up later and seek other means. I am not a welder nor do I have access to one either so doing this myself is not an option. Just a phone call later and I was quoted another price of #290 each installed - a lot more in my price range. Strikes me as odd that the first guy quoted parts alone at $968 for the front cat (includes Pipe) and $370 for the Rear. I was almost sick after the first quote, hell I only paid $3500 for the van to begin with.

I have seen Magnaflow systems out there for ~$350 including the Y-Pipe, flange to flange. That is a more likely scenario for a Do It myself task - but I can just see the Manifold bolt snapping off leaving me stranded though. In the past those bolts always broke on me.

Does anyone else have experience replacing these Cats? Mine is a 2001 2WD Ls, if there is more specific knowledge out there. As it is Easter I have to wait until Monday at the earliest to have it done.

 

[ALPO]

I ordered the Walker replacement part, includes the Y-Pipe and Cats back to the flange for the muffler. It cost me roughly $400 and a mechanic around the corner said he can put it on (he has a lift in his shop and routinely does exhaust work. As mentioned the bolts look like they just might give me issue so it's better off letting him do the work). I'll keep the forum posted on my progress.

I still can not believe the first shop giving me that price - must have thought I was desparate enough to provide him over a thousand dollars just for the labour.

 

[astroturf]

I ordered the Walker replacement part, includes the Y-Pipe and Cats back to the flange for the muffler. It cost me roughly $400 and a mechanic around the corner said he can put it on (he has a lift in his shop and routinely does exhaust work. As mentioned the bolts look like they just might give me issue so it's better off letting him do the work). I'll keep the forum posted on my progress.

I still can not believe the first shop giving me that price - must have thought I was desparate enough to provide him over a thousand dollars just for the labour.

Is Walker a stock cat? Are you going to replace the o2 sensors? Thanks for the update and please keep us posted. Jim