Catalytic Converter - Roadtrek Chevy 3500

[bwatters60]

Picked up my Roadtrek ('08 210P on an '07 Chevy Express 3500 chassis) from the dealer who had replaced both the oil pan and timing chain cover gaskets, and on the short drive home the check engine light came on and stayed on. Performance didn't change so I continued home and plugged in my scan gauge, which produced a P0430 code. Considering the possibility that something may have be done during the gasket job to cause this light to come on, I returned it to the dealer.

The dealer informed me today that it looks like one of the catalytic converters is bad. They said they're going to perform one more test to confirm. Ballpark estimate is a grand to replace.

My rig has 147,300 miles on it (looks and runs great, everything works, and I plan on keeping it another 4-5 years). If the one converter has to be replaced, should I just tell them to replace the other converter to avoid the misery of it failing while on a trip? Has anyone with high mileage Express 3500's had issues with or failures of their catalytic converters?

Thanks!

[themexicandoctor]

Originally Posted by bwatters60

Picked up my Roadtrek ('08 210P on an '07 Chevy Express 3500 chassis) from the dealer who had replaced both the oil pan and timing chain cover gaskets, and on the short drive home the check engine light came on and stayed on. Performance didn't change so I continued home and plugged in my scan gauge, which produced a P0430 code. Considering the possibility that something may have be done during the gasket job to cause this light to come on, I returned it to the dealer.

The dealer informed me today that it looks like one of the catalytic converters is bad. They said they're going to perform one more test to confirm. Ballpark estimate is a grand to replace.

My rig has 147,300 miles on it (looks and runs great, everything works, and I plan on keeping it another 4-5 years). If the one converter has to be replaced, should I just tell them to replace the other converter to avoid the misery of it failing while on a trip? Has anyone with high mileage Express 3500's had issues with or failures of their catalytic converters?

Thanks!

I am sure you have checked the Fuel Cap & driven 50 miles (and that the dealership are telling you the Truth).

Is it the Oxygen Sensors OR the Cats themselves?

I had a difficult time resolving the Oxygen Sensors because of all Roadtrek hardware underneath - I did not do it but paid a young Mechanix who didn't pay attention & the issue wasn't the 02 Sensor #3 or #4 but an intermittment loose wire that will eventually used silicone on.

[bwatters60]

Didn't think of the gas cap. Suspecting it may have been caused by something done at the dealers shop (they have been very good so I don't suspect anything malicious, etc.), I just wanted to return it to them as is and let them check it over.

However, if they do recommend catalytic converter replacement next week, I'll have a lot more questions for them after watching this excellent video!

https://www.engine-codes.com/p0430_chevrolet.html

Thanks,
Bruce

[mloganusda]

You might want to take it to a muffler shop for replacement as they should be well under price stated by dealer.

[otr]

Personally I try to avoid the dealer for car work except when dealing with recalls. I have a great small independant shop which I have worked with for 10 years. John is a great diagnostician and generally can finds ways to do things much more economical than dealer OEM products, just my 2 cents worth.

[gklugie]

I replaced both of mine ( 2002 with 75,000 miles). I went to a small local independent muffler specialist shop. He was quick and cheap.

[bwatters60]

UPDATE: Well the dealer diagnosed the engine code due to failure of the catalytic converter (due to disintegration of the internal substrate). I requested a quote for replacement of both converters and it came to almost $3600, which included replacement of all oxygen sensors (added almost $500, and I didn't need these since I had replaced all four at around 100k miles). And the really bad news was that the dealer couldn't get the parts. That was sad because they supply all Chevrolet parts for the nation! Earlier I had checked the GM Parts Direct website and the converters were offered but not in stock, and the estimated ship date was 2 months out. So OEM catalytic converters for '07 3500 Express vans are in short supply!

My advisor suggested I take it to a local muffler shop that they frequently use and the cost would be less than half of the dealer quote. The muffler shop would use an aftermarket converter, but given my Chevy was an '07 it would work fine (he and other service advisors informed me that the newer cars/trucks have problems with the aftermarket converters).

I've been shopping online for parts tonight and tomorrow I'm going to get under the van and scope out doing the project myself. As long as there's no welding required, I have the tools, the ramps, and the time, so why not!

Thanks to all for your suggestions!

Bruce

[Jon in AZ]

Failure of the substrate is a high priority repair. Every year, numerous wildfires are attributed to crumbling pieces of failed catalytic converters spewing out the tailpipe.

Glad you have found the cause and a solution!

[ChicagoTom]

oxygen sensor may be bad...

[ChicagoTom]

I would get a second opinion..oxygen sensor may be bad..

[bwatters60]

Little cold today to work outside, so I'm doing more research. Planning on testing the oxygen sensors on bank 2 (pass side) tomorrow, and we'll go from there!

[themexicandoctor]

ALERT ALERT ALERT;

A couple of years back my local friend & mechanic attended to my Roaftrek when I was receiving the CHECK ENGINE LIGHTS & it turned out to be Oxygen Sensor #3 & #2 (or maybe 4)

I replaced them.

Within 100 miles in came back on, #3.

I replaced it again, free of charge.

Then it came back on again & again.

Bottom line; when a bearing/control arm/whatever required me to seek mechanical attention on the other side of town, a very accomplished & dedicated older mechanic looked at my problem & solved it in 5 minutes.

It was a loose/uninsulated wire that simply needed some silicone. Never, ever had a problem since.

My friend's employee was a younger mechanic/let's not investigate the issue fully & just plug in a new sensor.

Part of the problem with the Sensors 3 & maybe 4 is that access to them & the wiring is very limited because of the Roadtrek configuration underneath & I think some vibrational chafing. It was more difficult to carefully examine the entire problem than to plug in a new unit.

I hope this helps.

[bwatters60]

Originally Posted by themexicandoctor

ALERT ALERT ALERT;

A couple of years back my local friend & mechanic attended to my Roaftrek when I was receiving the CHECK ENGINE LIGHTS & it turned out to be Oxygen Sensor #3 & #2 (or maybe 4)

I replaced them.

Within 100 miles in came back on, #3.

I replaced it again, free of charge.

Then it came back on again & again.

Bottom line; when a bearing/control arm/whatever required me to seek mechanical attention on the other side of town, a very accomplished & dedicated older mechanic looked at my problem & solved it in 5 minutes.

It was a loose/uninsulated wire that simply needed some silicone. Never, ever had a problem since.

My friend's employee was a younger mechanic/let's not investigate the issue fully & just plug in a new sensor.

Part of the problem with the Sensors 3 & maybe 4 is that access to them & the wiring is very limited because of the Roadtrek configuration underneath & I think some vibrational chafing. It was more difficult to carefully examine the entire problem than to plug in a new unit.

I hope this helps.

Well that's interesting. Thanks for taking the time to write that up.

Since I cleared the P0430 code I've driven about 140 miles and the check engine light has remained off, and the CAT symbol on the I/M Readiness screen of my Nexpeak ODBII scanner has gone from a red "X" to a green checkmark. So all appears to be well.

Voltages from my oxygen sensors, which I replaced all four about 50K miles ago, appear to be normal according to my Nexpeak. Inspection underneath didn't reveal anything obvious like loose wires, bad connections, etc..

After a little more research today I did learn to tap on the on the catalytic converter to see if there's anything loose inside (if so, it's probably time to replace). So I need to get back underneath and try that. The other thing I learned today was about a product to clean catalytic converters. Reviews were good as it appears to have solved converter issues for many. So I ordered a couple bottles (Amazon has a good price on two bottles). My objective is that it should clean my converters, if they are dirty, and prevent future problems. After all my RT has over 147K miles.

Unfortunately I've also had a red "X" for my EVAP on the scanner I/M Readiness screen, and this hasn't cleared. The scanner tells me that Evap system leak test failed. My gas cap clicks normally when closing and the rubber seal looks good, so research tells me to check the EVAP purge solenoid valve. That's relatively easy to that's on my to do list for tomorrow!
Thanks again!
Bruce

[CareyM]

1/ an easy cat con test is to put an infrared thermometer on the upstream pipe , eta temp reading , then the a downstream temp reading after the cat con. if the temp difference is more than 50 degrees, suspect a problem. 2. rock auto has aftermarket cat cons for about $250 for our express vans. 3/ if the gm dealer is lazy thy'll not want to unscrew yr old o 2 sensors, GM prefers to throw in 4 new o 2 sensors for $ 800. (what a waste of my money ) 4. there is one o 2 sensor 9upstream, can't recall which bank b1 riverside or b2 passenger side ) which is hard to get to, so sloppy mechanics either dont screw it in fully or mess up the wires to it. if an upstream o2 sensor is giving bad readings because the wire is abrading on something or the sensor isnt installed tight , that bad signal from that o 2 sensor tells th e c u to alter fuel flow into the injectors. bad installs of good o 2 sensors can also give the dread p 0300 r andom cylinder misfire code.

[themexicandoctor]

PS. I just replaced another Oxygen Sensor in my unit, according to the mechanic there is some sharp sheet metal underneath that the insulated wires rub against.

Heads up for anyone with a 2004-2006

[CareyM]

I'm investigating adding a catalytic converter cleaner to my gas tank on my roadtrek 07 chevy 3500 express 190P . I think the reviews on various sites show some good results when you run Cata Clean or Dura ton catalytic converter cleaner into 1 or 2 tanks of gas per the instructions. these products are 17 to 23 per liter and you run them into your 1/2 full gas tank and drive 100 miles or so. the reviewers say these products work and they're a lot cheaper than a new cat converter. . .

[themexicandoctor]

If that proves accurate in reality, Thank You.

I do know on a Motorcycle those additives are effective.

[bwatters60]

2/15/22 UPDATE: I have not replaced my catalytic converters and I've driven my Roadtrek about 150 miles with no engine codes. So far I've:
1) inspected the O2 sensor wiring and found no issues.
2) tapped on the converters with a mallet and heard nothing loose inside.
3) observed the O2 sensors with my ODBII scanner and found the voltage produced by the upstream sensors vary continually between 0.2-0.8V, while the downstream sensors practically flat lined at about 0.68V and 0.75V, so all appear normal.
4) with the engine at normal operating temperature, checked temperatures at the inlet and outlet of the converters - both show a 50-100F degree
difference between the inlet and outlet of the converters (about 300F at the inlet and about 400F at the outlet), so again all appears to be normal.

During the testing I also found a defective (leaking) vapor cannister purge valve and replaced it. It didn't produce a code but my ODBII scanner was indicating "EVAP emission system leak test failed". The scanner indication hasn't changed so next steps planned are to inspect hoses/connections underneath, and possibly replace the gas cap.

My RT runs and sounds normal, and based on all my research, I've been unable to determine the cause of my P0430 code. I have purchased a couple of bottles of Cataclean, but have not run my gas tank low enough to use this additive yet (need to add the first bottle at about 1/4 tank full, drive it 15-20 miles, then fill up and add the second bottle).

Thanks for all the suggestions.

Bruce