Exhaust Emissions

[jed50]

Has anybody heard this one before? Nov.2000. 1.8vvti GS. Last April 06. took car for MOT. Failed on emissions. New cat did not cure it so took to garage to check it out (not Mr.T) Was told it was lambda sensors (bank 1 and 2) So they replaced both (£130 each!) ( Just before MOT, eng.man. light came on) Car passed MOT and light went out. A week or two later light came back on again so took it back and garage could find no fault. Light been on and off all year but car still runs perfect and does 37 to 41 mpg. Now to April 07, MOT again and back to same garage and same prob. Fail on emissions. Everything inc. lambdas check out ok. Garage said they spoke to Mr T tech. dept they said it could be throttle body seal and/or vacuum pipe to brake servo pulling air. Replaced these and still no good. So back to Mr T again this time they say it could be a stretched timing chain!!! A new one on me. They say that sometimes the oilways in the block get clogged and starve the chain of oil and so stretch it and that could affect the emissions. Surely if timing chain or tensioner goes you would here it rattling? Think i'll try another garage. Sorry this is so long but you try to get as much info in as you can dont you? Hope someone can help with this one i've lost all my hair with it!!!

[Steve84]

Cannot tell you a cure. but can tell you your not alone. We have failed a couple 1.8 vvt-i avensis on emissions at work. We sell loads of toyotas at my work place and cannont find a cure. We have checked cats, o2 senosrs, Valve clearance still the emissons are out. The only way we have passed them in the end is to use a fuel cleaner additive and thrash the living daylights out of the car test it when red hot and they just meet the limits. All the cars engines are not known oil burners either.

[jed50]

Cannot tell you a cure. but can tell you your not alone. We have failed a couple 1.8 vvt-i avensis on emissions at work. We sell loads of toyotas at my work place and cannont find a cure. We have checked cats, o2 senosrs, Valve clearance still the emissons are out. The only way we have passed them in the end is to use a fuel cleaner additive and thrash the living daylights out of the car test it when red hot and they just meet the limits. All the cars engines are not known oil burners either.

Thanks Steve. Had a price for replacing timing chain and tensioner from garage that checked it out, £700 approx. Think i'll ring Toyota and a couple of other garages and see what they say, but i think i'll try fuel cleaner and the thrashing first, i've got nothing to lose,i'll post results