mr02mcg Posted February 19, 2013 Report Share Posted February 19, 2013 ok so my car is failing on emissions, it has been running rough for a while now. results are fast idle test co% max limit 0.300 actual 0.363 hc max limit 200 actual 449 lambda min limit 0.970 max limit 1.030 actual 1.049 second fast idle test co% max limit 0.300 actual 0.380 hc max limit 200 actual 493 lambda min limit 0.970 max limit 1.030 actual 1.046 natural idle test co% max limit 0500 actual 0.353 (only pass on the full thing) I would appreciate any help on this as i dont want to just start throwing parts at the car, Thanks Martin Link to comment Share on other sites More sharing options...
cooperman Posted February 19, 2013 Report Share Posted February 19, 2013 if there are no holes in the exhaust system and your obd is not showing errors then its all about trial and error. parts to check/replace are: lambda sensor/s cat maf not looked at the gen 7 workshop manual but there many be a way of testing the lambda sensor, like on older cars it give you a measurement you can get with a multi meter. if not in limits it needs changing. cat there is no way of testing as such and is just a replace if nothing else helps. maf im sure there is a way of testing this as well like the lambda. and generally its just a matter of cleaning this out properly. nothing is easy here and having a garage test/inspect these things could end up costing you more than just biting the bullet and getting lambda and cat changed. maf like said is just a clean job and im sure there are guides in the gen 7 bit. hope that helps andy Link to comment Share on other sites More sharing options...
mr02mcg Posted February 19, 2013 Author Report Share Posted February 19, 2013 cheers for the quick reply andy, i had a look around online and it says high hcs is usually down to combustion ie ignition parts etc and that would tie in with the backfiring from the exhaust sometimes and the slight hesitation it has. the co% has me at a loss as i have had the cat replaced and the first lambda changed and it didnt make a difference, i also bought another maf to put on it but when i put it on it was really rough and wouldnt rev properly so put the old one back on and it revved again. its been doing my box in for a while and i just want it sorted grrrrr. Link to comment Share on other sites More sharing options...
cooperman Posted February 19, 2013 Report Share Posted February 19, 2013 well in that case then if you have done all the above then the only thing i can think of is. the lambda, if it has 2 work together. the first being before the cat and the second being after the cat. if you have change one/pre cat, this only measures whats going in to the cat and then compares to what comes out via the post cat lambda. if the pre cat one is the one you changed then this is the one that measures the dirty exhaust gases the post cat one measures the clean exhaust gases. if the post cat one if fubar then it could think that the cat is working more efficient than it is and adding more fuel. (only adding more fuel because thats what toyota love to do, as its safer on the engine lifespan). other thing to consider are things like service parts. if the spark plugs for example are not working right (old) or not gaped right then it will not be burning the fuel properly/fully. Link to comment Share on other sites More sharing options...
Cravo Posted February 19, 2013 Report Share Posted February 19, 2013 mine was overfuelling so I did the following Cleaned MAF Changed Air Filter Changed Spark plugs and it passed the emissions test which I am pretty sure it wouldnt have done before when it was overfuelling. Try this first but the lambda is a more expensive fix as there are 2 of them and about £60 a piece. Link to comment Share on other sites More sharing options...
harv_j Posted February 19, 2013 Report Share Posted February 19, 2013 You're not having a good day are you pal. Link to comment Share on other sites More sharing options...
mr02mcg Posted February 19, 2013 Author Report Share Posted February 19, 2013 My air filter is a blitz sonic power induction kit. My plugs were changed and made no difference and the maf is clean. It is deffo overfuelling though. Does the high hc contribute to high co or vice versa? I was thinking of going down the ignition route to see if that was to blame. Link to comment Share on other sites More sharing options...
Cravo Posted February 19, 2013 Report Share Posted February 19, 2013 The lambda is running high fella so I would place my bets on that mate I'm afraid. I had a similar problem with a 306 and just turned the fuel pump down and it solved it don't know if that's possible on the 7 though. Link to comment Share on other sites More sharing options...
mr02mcg Posted February 19, 2013 Author Report Share Posted February 19, 2013 Good shout on turning down the fuelling. If i could get someone to test the lambda and say it was definately that then i would happily buy a new one. but what i dont want to do is buy loads of stuff and not sort it if you know what i mean. I got the cat changed under warranty and the front lambda changed and it made no difference. I dont want to change the rear lambda and be told the front one aint working right. Its really really bugging me now. Link to comment Share on other sites More sharing options...
ams Posted February 19, 2013 Report Share Posted February 19, 2013 (edited) My air filter is a blitz sonic power induction kit. My plugs were changed and made no difference and the maf is clean. It is deffo overfuelling though. Clean the air filter - I see too many people with induction kits that are completely blocked. Next check plugs and replace if needed Clean maf - also check that there are no leaks where the maf plugs into the induction kit, and no leaks betwen induction and throttle body if its still not right then change pre-cat sensor - post cat sensor on 7 does not affect fueling. Edited February 19, 2013 by ams Link to comment Share on other sites More sharing options...
Cravo Posted February 19, 2013 Report Share Posted February 19, 2013 My knowledge is exhausted now then fella, like I said if you are able to turn down the fuelling then that might work temporarily to get through the MOT. Ams might know if this is possible. Link to comment Share on other sites More sharing options...
J03 Posted February 19, 2013 Report Share Posted February 19, 2013 (edited) mine was overfuelling so I did the following Cleaned MAF Changed Air Filter Changed Spark plugs and it passed the emissions test which I am pretty sure it wouldnt have done before when it was overfuelling. Try this first but the lambda is a more expensive fix as there are 2 of them and about £60 a piece. Mine passed MOT fine when it was overfuelling matey Good shout on turning down the fuelling. If i could get someone to test the lambda and say it was definately that then i would happily buy a new one. but what i dont want to do is buy loads of stuff and not sort it if you know what i mean. I got the cat changed under warranty and the front lambda changed and it made no difference. I dont want to change the rear lambda and be told the front one aint working right. Its really really bugging me now. Has it thrown CEL p0420 bud? I have changed both sensors & had a new CAT as well & recently it's thrown the code twice, so go figure? My emission results & fuelling are bob on though For the relatively little outlay, it's worth changing the precat sensor as it has a big impact on fuelling. Running too rich is going to waste fuel & eventually smoke the cat, so it's a false economy to keep the old one in. Edited February 19, 2013 by J03 Link to comment Share on other sites More sharing options...
mr02mcg Posted February 19, 2013 Author Report Share Posted February 19, 2013 Lets just say it went through mot with a wink. I wanna fix it yhough Link to comment Share on other sites More sharing options...
Recommended Posts