Hello,

I'm trying to find the reason of a P0420 error code, with a strong gas smells at the exhausts (which make it fails the emission test).
Yesterday I removed the downstream O2 sensors to look inside the catalytic converters with an endoscope camera: the driver cat seems fine, the passenger is completely hollow...

Before I change them with all O2 sensors to be safe, I wanted to check with off-read H or X pipes owners: does your car smell bad?
Because mine stinks on both exhausts even if the driver side cat seems good. I saw they are connected, but I'm not sure if it's like an H-pipe or just a bracket.
I would like to rule out an engine issue, I realised that the idle is too low, it can stalls if there is a bump while I'm reversing.

PS: all OEM cats are out of stock, I guess I must buy a C.A.R.B. compliant replacement?

 

define "smells bad" LOL ... like rotten egg sulfur bad? or old-fashioned muscle car unburnt fuel bad?

yes off-road pipes make the car smell like an old school muscle car, due to the lack of cats ... so yeah that could be coming from the empty-cat side, and yes the h-pipe connects them

the P0420 code means that the catalytic converter is not working, which makes sense if it is empty; O2 sensor is probably fine

you probably need to check your local regs regarding the CARB requirement, where do you live?

 

FIXED

 

I wouldn't say it smells as good () as an old car, but it's definitely a strong smell of unburnt (or overburnt?) fuel.
I'm curious, what a rotten egg sulfur smell would mean?

Thanks for confirming that they are connected.

I live in France, which is really strict about emissions. During the car inspection (every two years), a 2002+ car is limited to 0.3% of carbon monoxide emission during idle, 0.2% at 2500 rpm.
There are a lot of documents on the on the official CA website but I couldn't easily find something to compare.

 

The only replacement for the "OEM" catalytic exhaust system which is also OEM grade to my knowledge, is manufactured by Magnaflow... Link and image are provided below, if interested!

https://www.magnaflow.com/products/4...ytic-converter

 

If you have anything off road or cat delete stuff and YOU NEED to pass emissions testing,.......you're going to be replacing that stuff. You will not pass.
You will fail every single time until it is back to stock or not "off road" or "cat delete" related.

 

Exactly 100% spot on Tony!

 

yeah in France I think it is risky with anything other than OEM cats, but from first post it sounds like that might not be an option

CARB certification might be a good sign, but I think all that means is that someone in California got paid to test and sign off on that product, not sure that means it will meet the requirements in France

 

Send me Your Vin And I will Check a Few Things Out For You! Parts is Kinda My thing! Email it to clevparts@aol.com and I will send you Back Some Info which maybe Helpful.

KC

 

Thank you, but the OEM grade #49001 seems to be replaced with the HM grade #24151. They also have the CARB grade #5461001 but it's $3500!

On RockAuto there is a Walker CARB grade at $1500, but the cats seem smaller and it's not mandrel-bent tubing, not sure if it can restricts the air flow.



That's what I'm confused about, if "OEM grade" is worse than CARB grade, does that mean that Ford was installing different cats if the car was sold in California?



Thank you, will do!

 

I am not sure about that .... I thought "CARB" was a certification for aftermarket auto parts, to confirm that they meet California's (ridiculous) requirements. If that is the case, then OEM should be "original Ford" and CARB means aftermarket that meets CA requirements. But I do not understand what is "OEM Grade"?

And yes there are special California requirements that must be met on new cars being sold in California, but I thought "CARB" was for aftermarket ... sorry that is not much help ... but here is a link that might help
What CARB and CARB Compliant Actually Means | Metromile