Ok so ive been trying to help a mate out with his ef but ive run out of ideas. Its a ef with duel fuel. And ever since my mate swapped over the o2 sensor, petrol then ran rough on idle. So my mate swapped the old one back in and this is when all the trouble started. Ever since putting the old one back in the car consistently backfire on gas when you drive anything above grandpa style driving. And it is even starting to backfire on petrol now too. The car has already blown up 3 intakes and enough is enough.

The gas setup is the one where you have the complicated mixer near the brake booster and uses the vacumm setup. My mate has even tried swapping it for the old carby setup where the mixer is on the intake but the car is still no good.

The car has done low km's and the leads would only be about 20 000kms old. The car doesnt get driven much and now with the backfiring its getting driven less and less as my mate doesnt want to risk any more backfires.

Anyone got any ideas.

spark plugs or coils, Also if it had a dissy i'd say ignition timing, but it doesnt, so maybe something else is upsetting the ignition timing.

Gab

Why did ya mate change the oxy sensor.Did he get the correct type.The oxygen sensor I think is coursing it as it does ya fuel air mixture and I think there is too much gas goin in and on petrol the same as both can flood and the engine is taking too much and that is where I think the back fire is comin from