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Discussion Starter #1
Hi, Im new to the forum but hope one of you can help....

My Civic 1.8 VTi failed its MOT due to a number of things (most now sorted) but the main one is emissions.
Results were :
1st Fast Idle test
CO 4.15%
HC 171ppm
Lambda 0.89

2nd Fast Idle test
CO 8.40%
HC 351ppm
Lambda 0.78

passed natural idle test.

Ive replaced the air filter, the spark plugs are clean, its had additive in the fuel, mechanic checked valve clearance and Honda couldn't confirm the fault through their diagnostic what the issue is.

Any ideas?? Its a 98, R plate.

Im going down the replacement ECU/remap existing ECU route but a replacement is £100 ++++ and finding a garage that can remap my car is a nightmare.

Thanks in advance.
Tris
 

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did you ensure your car was right upto normal operating temperature before you put it in for the test because you need to make sure your catylitic converter has warmed up nicely?? your cat may even be at the end of its days!? did they change the pvc valve aswell??


when was the last time you changed the oil??
 

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nickyboy said:
My money is on the catalytic converoter.
Cat would be on my list ,
you also may have an oxygen sensor gone down
and the only other thing it would be is the ECU temp sensor keeping the engines fuel enrichment to high with false readings ,basically telling the ECU the engine is still cold when its not.
 

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would resetting his ecu solve that issue with the ecu temp sensor?
 

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Discussion Starter #7
josh897
unfortunately I had to leave my car at the garage and they MOT'd it later in the day so it wouldnt have been hot when it went in. The valve wasnt changed. New oil and filter about a week before the MOT.

I keep getting told that its over fueling and maybe to get it to run lean - maybe take the filter out the air box - anyone tried/heard anyone do that?

Does anyone with knowledge of Hondas diagnostics know whether there plug in would locate issues with lambda/cat or temp sensors though? Im a bit annoyed that taking it to the dealer didnt give any firm answers and there suggestions (valve clearance) haven't helped at all.
 

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well thats your problem then, you need your car to be up at normal running temperature, the cat needs to be hot for it to work efficiently!!

but tbh the garage should have had the sense to let the engine run upto normal temp before they put it through because that will make it fail on emissions straight away!!
 

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Discussion Starter #10
I would love to blame the garage but it had a retest at a different place with the same results - although again im presuming it sat before going in.......
Thanks with the replies from everyone, will let you know what happens.
Tris
 

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take it upto the test center yourself and have it heated right up on the way!!

but nah i would say the mechanics probably would have had the sense to let it run for a bit before the test
 

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josh897 said:
take it upto the test center yourself and have it heated right up on the way!!

but nah i would say the mechanics probably would have had the sense to let it run for a bit before the test
cars in this cold weather need to come off the road and tested straight away as the cats cool down too quickly
if its slightly iffy thats the best way todo it .
 

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My civic failed emissions coz it had a cone filter on it and it messed all the sensor readings up...even after i took it off.

My lambda sensor needed replacing but my cat was fine, i just took it for a absolute hammer before i took it in. All the garages i know get the car hot to get it through, if it a main dealer they wont coz they want you to pay money to "repair" it.
Get friendly with a local scrap yard and ask to borrow a cat, or ask a civic friend to borrow thers for the MoT... get it through then change it back.

Also big help "injector cleaner" which cleans your injectors and lowers your emissions but its for cleaning ur injectors not for making it pass an MoT... ;)
But should you choose to clean ur injectors whilst having an MoT.

Dunno if that helps...probs not. :D
 
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