new guy fighting cat/O2 problems...

[catnfool]

Hello there- I just found you guys, and it appears you may have the "silver bullet" to my problem!! For one, my old man's 02 Cummins blows my doors off; but we will get to that later... I keep getting a p420/p430 code and my poor old girl will start a mild "buck" ad lower speeds. I have replaced one 02 sensor(drivers side rear) and am not rich enough to keep guessing on them!!!! I have 172k on the original engine and not a drip/smoke anywhere!!

 

Thanks in advance, and I sure would like to know how to smoke the cummins!! bruce

[vhato]

Hello there- I just found you guys, and it appears you may have the "silver bullet" to my problem!! For one, my old man's 02 Cummins blows my doors off; but we will get to that later... I keep getting a p420/p430 code and my poor old girl will start a mild "buck" ad lower speeds. I have replaced one 02 sensor(drivers side rear) and am not rich enough to keep guessing on them!!!! I have 172k on the original engine and not a drip/smoke anywhere!!

 

Thanks in advance, and I sure would like to know how to smoke the cummins!! bruce

 

<{POST_SNAPBACK}>

 

 

 

 

Well,

Assuming whoever puled the codes is telling you all the codes, lets get started.

 

p0420 means the drivers side catalytic converter is below any usuable efficiency.

p0430 means the passenger side catalytic converter is not as efficient as it was.

 

In lamens terms, your drivers cat is clogged..bad and causing your mild buck and your passenger side is on its way there.

 

It is indeed possible your after-cat o2 sensors are both bad, but I *HIGHLY* doubt it. Considering you have a V-8 w/aftermarket intake and/or other mods I would say you are running rich most of the time. Your MAF is possibly out of calibration due to your mods (very possible) or you are Wide Open....ALOT, constantly racing your truck.

 

The good news is, by changing both CATS you will regain a SERIOUS amount of power as well as increase fuel economy. If you have less than 80,000 miles, your GM Dealer MUST replace them for free. If not, you can go to your local muffler shop and buy two Cat-Co high flow converters for ~$110 a piece. Then you gotta figure out what caused them to fail. Hauling a$$ too much, programmer or an MAF not calibrated to your new mods (custom tune will fix it, not a handheld programmer, unless you get a Predadtor and DiabloSport Tunes it via the Internet). Running rich will just clogg them up again and running lean will burn them out.

[catnfool]

WOW, that was a whole lot of info quick!! Thanks! I also heard of an "IMCO" brand Y pipe with high flo cats already installed for around $300, but I didn't want to buy that and be wrong... Has anyone bought this? I never noticed an increase with the airaid spacer, so I will probably take it off if it "could" be a cause of codes. plus it whistles like a vacume leak!

 

Thanks again for the help- I hope this will help take care of the Cummins problem I have!

[vhato]

WOW, that was a whole lot of info quick!! Thanks! I also heard of an "IMCO" brand Y pipe with high flo cats already installed for around $300, but I didn't want to buy that and be wrong... Has anyone bought this? I never noticed an increase with the airaid spacer, so I will probably take it off if it "could" be a cause of codes. plus it whistles like a vacume leak!

 

Thanks again for the help- I hope this will help take care of the Cummins problem I have!

 

<{POST_SNAPBACK}>

 

 

 

 

Nah, IMO spacers for MPFI engines are gimmik, but it wouldn't change enough for the engine to fight a rich state.