Emissions Diagnosis P0420

[Guest]

Hi - this is a bit of a cry for help!

I have a 2000, 1.8 Celica (140 bhp).

Had P0420 and P0171 fault codes. I cleaned the MAF and replaced spark plugs and pre-cat sensor which didn't help so, I took it for a diagnostics at the local garage.

They basically said the cat had died and needed to be replaced because it had high C02 emissions indicating that. So on their advice, I had the cat replaced.

This cleared the P0171 code, but P0420 is still there. It's a Catalyst System efficiency running lean on Bank 1 error.

At this stage, my last thought is I should run a smoke test to check for leaks in the header or manifold. I've spent £350 and haven't yet fixed this so any help or advice would be massively appreciated!

All the best

[roks]

On Monday, December 01, 2014 at 7:16 PM, MattRowbotham said:

Hi - this is a bit of a cry for help!

I have a 2000, 1.8 Celica (140 bhp).

Had P0420 and P0171 fault codes. I cleaned the MAF and replaced spark plugs and pre-cat sensor which didn't help so, I took it for a diagnostics at the local garage.

They basically said the cat had died and needed to be replaced because it had high C02 emissions indicating that. So on their advice, I had the cat replaced.

This cleared the P0171 code, but P0420 is still there. It's a Catalyst System efficiency running lean on Bank 1 error.

At this stage, my last thought is I should run a smoke test to check for leaks in the header or manifold. I've spent £350 and haven't yet fixed this so any help or advice would be massively appreciated!

All the best

Hi, 

Did you manage to fix this? What was the problem?

Was there any leaks? I am having the same issue with p0420 but passes mot no problem. 

Thanks