Dc5 failed emissions help

Jamie141

Hi I'm looking for some advice I recently failed my emmisons on the nct on high and low idle car is a 2004 honda integra dc5 milage 120000 kilometres I'll post results now

Rpm 880 Low idle Co was 0.90 vol
Hc 61pm

Rpm 2260 High idle Co was 0.88 vol
Hc 64pm

And lamba 0.98 which is a pass
So as you can see Co readings are very high I put a second hand cat in so basically what I'm asking is do you think I should replace the cat again or the lamba sensors based on them results and help would be much appreciated

Mech1

air filter clean?

Jamie141

Yes it has a aftermarket air intake would a air filter cause it so be so high?

CJhaughey

I'd fit a new cat, a secondhand cat is a luckybag with low odds.

mullingar

High co usually indicates running rich or a dead cat.

Is the MAF sensor in the same diameter air pipe as the original? If it's a larger diameter, it's going to misread the true volume of air entering the engine.

Cee-Jay-Cee

A second hand cat could have been lying in a shed for the last 5 years, I would go and get a new cat (you can get universal cats which will be cheaper than an OE one from Honda)

Stoolbend

Universal cats are muck. A genuine second hand cat that could be welded in would be a better option.

Cee-Jay-Cee

Stoolbend wrote: »

Universal cats are muck. A genuine second hand cat that could be welded in would be a better option.

Why would you weld it in, if its a genuine Honda cat then it'll bolt on. I had a DC2 ITR fail emissions years ago and had it checked and was told cat had failed. I couldn't find a second hand cat that I could guarantee was working properly so I had a universal cat fitted (flanges of the old cat were welded onto it) and it flew through the test, I removed it after and fitted a straight pipe.