ive used easy obdii to view the lambda reading and got 0.8v steady, under load lifts to 0.9v, on lifting off drops to 0.3v before lifting again to 0.8v so im ***uming the lambdas ok?
if i disconnect the battery would that reset the ecu and possibly help?
Well yes, it would reset the ECU, but not sure if it'll help - the CO figures have overshot by quite a margin... cleaning the MAF sensor might help as well. The 2nd test was noticeably better, which might indicate that the engine had warmed up a bit compared to the 1st test, so was the engine as hot as it should be the start of the testing?
Mine just scraped through on emissions, I usually take mine for a Turin Tune-Up before it goes for test, however this time I left the car in the morning and it went in for test at 3pm.
I ***ume you have 2 lambda sensors (pre & post cat, or primary & seconday, or bank 0 & bank 1) - is there a noticeable difference in the readings? That'd show that the cat is working. I'm not that familiar with petrol Accords, but usually on petrol engines the fuelling feedback to the ECU comes from the pre-cat sensor, while the post cat sensor is only there to confirm to the ECU that the cat is making a difference (and therefore working) once the engine has fully warmed up... and you're not getting an ECU error message for this problem. I believe this suggests that the cat is OK.
I still think the Mot test was conducted before the cat had warmed up fully.
EDIT - I'd also clean the MAF sensor, just to be sure
under heavy/full load sensor 1 was 0.8 -
0.9v and sensor 2 was 0.025 - 0.035v
on overrun both sensors showed 0.00v
cruising along sensor 1 0.8v sensor 2 0.7 -
0.8v
on idle they show the same as cruising
The big difference in readings under heavy/full load (when the cat is working hardest) indicates that the cat is doing something and therefore functioning to at least some extent. So far as I can tell, it's probably OK.
