[firerescue121]

Was getting a p0420 code starting Jan 2021, I replaced upstream O2 per recommendation and ran some treatment through fuel to clean cat, codes went away car drive fine, sept 2021 car ran fine went and got fuel came home car ran fine, next day cranked to go to work temp was 70-75 in Texas and got out of the drive way, accelerated and refused to shift and wouldn’t go over 30 floored. Car died after I let of throttle, hard start following. Got it home car revs ok but goes to low rpm after sometimes dying. Changed plugs, checked injectors, changed upstream O2 again (per recommendation again) and still doing the same thing. Wondering if this is going to be a cat issue and how I should go about testing it. Was going to take off muffler and 1st cat from rear then try it and see what happens then take the manifold cat off of that didn’t work. Tbh I didn’t realize these cars had 2 cays, anyone else notice this. 2014 forte 1.8L

 

[noturbonoproblem]

Best I can say is clean the MAF (if your car has one -I don’t remember for these cars), and then go out and absolutely rip the thing to get everything nice and hot to try and clear out any buildup or anything in the cat. Maybe try pulling the negative lead on the battery for 15 mins too to do a reset on the computer

 

[noturbonoproblem]

Also P0420 is tripped by the downstream sensor. Upstream controls drivability and engine operation, downstream checks to make sure the cat is working at the proper efficiency

 

[mobileterminaluser]

Might be clogged?

 

[ForteGT2]

Might be clogged?

That's what I was thinking. I don't think most drivers are aware of what a catalytic converter looks like inside! It is practically equivalent to a window screen!

 

[firerescue121]

Might be clogged?

That’s what I’m thinking just got to try to figure out if it’s the one off the manifold or the one before the muffler now.

 

[mobileterminaluser]

One way to visually check.

Turn on the vehicle & let it idle, let it idle. No need to rev. If you see the glowing red, one or both are clogged.

I saw on a 07 Toyota Scion TC 2.4L that the exhaust header & cat glowed buring red after 5minutes of just idle. Causing problems.

I hollowed it out completely. No more problem. Still quiet. Was expecting some kind of Honda riced out/mower & weed eater sound. Nope, all quiet.

 

[mobileterminaluser]

Don't know if the videos on catalytic converter cleanings from & on YouTube university actually work.

Do to your local junk/salvage yard get a spare/just in case back up before messing with yours.

 

[mobileterminaluser]

From Scion TC cat

 

[mobileterminaluser]

 

[mobileterminaluser]

My 2010 Kia Forte Koup SX 2.4L 6MT has 2 cats. It's from Cali.