P0135 fault code won't clear

[fume1977]

I recently pulled a 160 out of storage that had been off the road for three years. It failed its mot on emissions amongst other things. I have thrown everything at it, new cat, plugs, leads full service etc. It has had both lambdas replaced, the pre cat one I have changed three times and is now a genuine MG-Rover bosch one. I have changed the battery (incase voltage was dropping in the old one) but i can't get rid of the P0135 fault. Sometimes i can drive all day with no problems then it will come on. The car runs fine doesn't use huge amounts of fuel and is not in limp mode. I have spoken to an auto electrician who is also stumped. Has anyone had the same problem?. I might just take the bulb out but i'd rather not

[whitetop]

Check the wiring, i had this problem and found it was a wire on the ecu side.

Make sure they are tight so no air is getting in or out as they need to be super tight, clean the contacts including the under floor one under the seat for the main cat, have you checked your back box? if its been standing things brake down and start blocking the air flow.

[fume1977]

Thats great thank you, the back box is the only part of the exhaust system i haven't replaced. I know they are prone to hold water so it may have rotted out. The wiring would explain why its so random

[whitetop]

The problem with zr/25 is water by the ecu, always been a problem, back box does hold water, if you are leaving the car for so long best advice is bag over the end or cork it, saved me buying a new one.