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mk4 astra emissions problem!!!

15K views 9 replies 5 participants last post by  Dav1d 
#1 ·
Hi
Have a problem with the mrs car its a mk4 astra 1.6 16v T reg
last years mot it failed its emissions test.so first thought is cat is broken so had new one fitted took it back and still failed so up next was the lambda sensor but after fitting this when driving normal every now and again the engine management light would come on it would go back out if you thrashed it a bit which was weird.it still failed mot so thought faulty cat so had this swapped over i then took it for its re test thrashed it to make sure cat was working nice good. and it pass so didnt think anything of it apart from engine light was still coming on. It now mot time again and yes its failed on emissions again you have the following:
(1) Exhaust emissions carbon monoxide content after 2nd fast idle excessive.
(2) Exhaust emissions lambda reading after 2nd fast idle outside specified limits.

Now i have changed the lambda sensor again which i thought would sort it the engine management light does not come on anymore.but it still failed :doh:
not having much luck with it so before i put another cat on anything else i could check?
 
#9 ·
Just been done paper clip test come up with code: 0135 Heated Exhaust Gas Oxygen (HEGO) sensor heater which is a weird one as its been changed twice now so after a quick look on net found this info:

If the average voltage from the lambda sensor is running high (more than 0.50V), it indicates a rich condition, possibly due to a bad MAP, MAF or Air Flow sensor or leaky injector. If the average voltage reading is running low (less than 0.45V), the mixture is running lean possibly due to a vacuum leak or because the sensor itself is bad.

If the lambda sensor continually reads high (rich), it will cause the engine computer to lean out the fuel mixture in an attempt to compensate for the rich reading. This can cause lean misfire, hesitation, stumbling, poor idle and high hydrocarbon emissions (from misfiring).


so could be a bad air flow meter then like some have said will give it a clean see if it make any diffrence if not buy a new one
 
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