[Corsa B 1993-2000] Corsa b 1.0 12v emissions fail

[Tom02]

[Taurus]

I think you've answered your own question - give it a thorough service, then give it a good blast on the motorway. If it's been unused for a while and needs servicing the omissions will always struggle. The cat may be lazy - make sure they get it really got before testing.

[Shytalk]

+1 with the oil change as a minimum, then take it for a decent run, either dual carriage way or motorway, that will help clear out the fueling and exhaust systems.

[Tom02]

Oil change done + filter, spark plugs and air filter now it runs lumpy and have engine light on! Hoping this will point to emissions problem..

[Taurus]

Check the code for the engine light.

Just bear in mind that if it's showing an O2 / Lambda code then 9 times out of 10 it's not the sensor itself. Since it's a feedback system that usually points to something throwing the exhaust gases out of parameter - which can be anything from a leak in the exhaust, air leak in the intake, sticking EGR (even if no EGR code is present), dud AFM (again no AFM code may be present.)

Running lumpy usually points to an over-rich mix, another potential suspect is the coolant temp sensor on the water pump. They are cheap and easy to replace.

[Tom02]

Could you tell me what code reader i need please i have an obd2 but its not linking? When the car is cold it struggles to start unless i put my foot lightly on the throttle, would this point to temp sensor? Thank you

[Taurus]

If you've got a laptop go for Opcom. Many of the generic readers struggle with the 12v engine.

Try unplugging the AFM, it will force the ECU into a default mode, see if it makes any difference. If it runs better, despite the EML being on, then it's likely to be a dud AFM. You can try cleaning it with carb cleaner, though it often kills them so only do it if you're pretty sure the AFM is stuffed. Make sure it's bone dry before reconnecting. If the AFM is dead then buy a Bosch one. Cheap versions are a waste of time.

[Tom02]

Ok thanks, i unplugged afm with no change but when i unplug the temp sender close to afm the revs pick up and it runs better.. You think it could be that? Would a faulty temp sender cause emissions to fail? Also would it accomidate for dirty oil/old plugs/dirty air filter.. So only when i changed those things it picked up the problem?

[Taurus]

[Tom02]

I changed the cts as were so cheap but still no joy, really need to plug it but kind of reluctant to spend out the money! Need to find someone local who already has the reader and wont charge silly amounts! Even once ive fixed the problem i imagine ill have to get it plugged in again to clear dash light?

[Taurus]

Say where you are and someone local might have Opcom

[Tom02]

Yeah good shout thanks, does opcom only work for vauxhalls? And how good is it?

[CorsaEdi]

Opcom is just for Vauxhall and is very good once you learn all the features, you can do a lot of things with it

[Tom02]

[CorsaEdi]

Buy it then charge anyone you know a tenner to read their codes