I'm Back! (P0421 CEL Code)

[Eggman]

Of course now that I think about it, I doubt the exhaust is covered under the drivetrain warranty anyway.

Good point. Aren't emissions components covered under a 7-year warranty as mandated by law?

Edit: I found a reference that might be helpful:

Source

Duration and Mileage Limits

• 5 years or 50,000 miles for catalytic converters, electronic emissions control components, PCV valves, EGR valves, engine computers, and on-board emissions diagnostic devices.
• 8 years or 80,000 miles for major emissions control components such as the catalytic converter, EGR system, engine control computer, and on-board emissions diagnostic devices.

It's not clear why they list a catalytic converter in both but you might want to rethink disassembling and soaking yours until you've talked with a service center?

[Fummins]

I once replaced a cat on a car for someone because a shop told them that's why it was throwing a cat code-either p0420 or p0421, I can't remember which. Seemed legit cause it was a turbo chevy that consumed oil... The owner was less than thrilled to have the cel light come back on days later with the same code, they didn't care about the cat but just wanted their cel off so the oem remote start would work. I don't know if they ever got it fixed before giving the car away.

[Eggman]

Any updates? I’m curious to know how the catalytic converter cleaning turned out.

[Navysteveo87]

No updates yet. Not a pressing issue due to the car running great (Just affecting my mpg). I hope to get this fixed by the summer and I will update this thread when it's done.

[Johnny Mullet]

Keep us posted!

[Navysteveo87]

O2 sensor spacer installed last night, CEL codes cleared. Now we wait (50 miles).

I did not remove or try to clean out the converter (but I did clean the carbon off the O2 sensor). The car has been running great so I'm trying this as my first step to pass emissions check

[Fummins]

How do they do emission testing there, visual check, tailpipe sniffer, scan for codes or a bit of everything?

[Navysteveo87]

A bit of everything. They plug their scanner into your obdII port and run the test electronically. Pre-obdII vehicles they used a sniffer in the tail pipe but they don't do that any longer because every vehicle that's older than 25 years old is exempt from emissions inspection.

I have two options....

1. Go there and they first visually check underneath the car (see pic). Then they run the test in your obdII port with their scanner

2. Run the test myself on their self-service kiosk.(no visual check) https://www.ohioecheck.info/pages/self-service-kiosk

[7milesout]

Hey NavySteve - What year model is your car? I've been cornfusing myself. The exhaust system drawing(s) online are the culprit. I think the drawings are correct, but I'm getting myself cornfused.

I'm back to thinking about yanking the 2nd catalyst. But when I pull up the drawings online I keep thinking, "yeah but there's only 1 cat." But actually there may be 2, because the drawing I'm attaching below IS SHOWING THE 2ND catalyst. This exhaust pipe attaches just after the first "monitored" catalyst.

I think I'm straight on that now ... but my post here is to ask you if you could confirm if I've got it correct now.

From left to right is, the 2nd cat, the muffler, then the resonator. No?

Thanks!

[Navysteveo87]

Hey 7miles. I own a 2015 DE 5 speed with 175k

We do indeed have two cats but the placement of the first one (off the exhaust manifold) is different from mine to yours (see pics and link below)



https://mirageforum.com/forum/showth...tic-converters