Accent failing emissions

[maxdaccent]

ok am a newbie on this site but wanted to start with this as its been bugging me know for a long time. I have a 2001 Hyundai Accent which has been modified it has a 4-1 manifold with the older models CAT which has 1 o2 sensor in front and 1 o2 sensor after plus a full 2 inch stainless exhaust system, CAI and uprated throttle body, yet it just will not pass emissions on an MOT is there abody that would be able to tell me WHY? ive has a sports CAT on and it didnt pass either so bought a standard 400cell CAT but still the same problem.

 

[MasterAuron]

Re: failing emissions

Buggered lambda? How does it run? Didn't the garage advise?

 

[maxdaccent]

Re: failing emissions

the car runs fine as far as im aware the engine check light is off but then it might come on meaning getting the dealer to turn it off but then it stays off for say 6 months if not a full year as had this problem for a few years now. no the garage havent really advised me as its a mate so it still passes it MOT its just ive never been happy with doing it that way and really would like the car fully legal the right way. if you see what im saying. the only thing i would say is that when its gone back the the dealer for then to scan it to turn the light off they have said CAT ineffiecent but it said that even when i first got it but i cant get any bigger CAT as its a 400CELL one at present which as far as im aware thats the same as the original one although that one was bolted to the old manifold which i got rid of when i had the 4-1 fitted.

 

[obi_waynne]

Re: failing emissions

Try it without the CAI and refit the standard air box. I do suspect it is running rich. Is the afm reporting correctly?

What readings are you getting on the MOT report? Is it far out?

Also try a long run with a tank of redex and some superunleaded. I'd also stick the sports catalyst back in.

 

[pgarner]

Re: failing emissions

can you get logs from the ECU when its running ?
fuel trims, airflow, lamba readings
what kind of MPG do you average driving normally

 

[Sid447]

Re: failing emissions

ok am a newbie on this site but wanted to start with this as its been bugging me know for a long time. I have a 2001 Hyundai Accent which has been modified it has a 4-1 manifold with the older models CAT which has 1 o2 sensor in front and 1 o2 sensor after plus a full 2 inch stainless exhaust system, CAI and uprated throttle body, yet it just will not pass emissions on an MOT is there abody that would be able to tell me WHY? ive has a sports CAT on and it didnt pass either so bought a standard 400cell CAT but still the same problem.

Assuming the o2's are working correctly,
the engine PCV system is doing it's job,
and the engine is in decent condition;
...the likely problem is your up-rated throttle body and also if you have modified the maf-sensor in any way (if one is fitted, as some Hyundais run speed density or maf-less).

 

[Country Bumpkin]

Re: failing emissions

Do you have the print out from the emission test ?

 

[lutonmatt]

Re: failing emissions

Do you have the print out from the emission test ?

just what i was going to say with out seeing what it is reading i cant tell you what is likey to be wrong

as i need to see how high it is reading