BMW Repair: BMW 520i 1995 failed emmissions test (lambda 1.07), coolant temperature sensor, bmw 520i

Question
Car lumpy on idle. will not rev until engine warms up.I keep car moving by changing up in gear until operating temperature reached. engine appears to smother if accelerated in low gear when cold.Mechanic replaced vacume pipe: says 'cat is OK: O2 sensor OK (never replaced)
Thanks in advance.

Answer
Hi

Are you sure the Lambda sensor is ok? Have you tried disconnecting the Lambda and then running the car? This will put the car into limp home mode but will give you an idea if the sensor is ok. There should be resistance between two of the terminals (about 1-15 Ohms)if you want to check it. Otherwise have a look at the Engine coolant temperature sensor, this should read at 2000/2500 Ohms at low temp (warm at +- 25 Deg) and about 600 Ohms at high (around 80 Deg). Hope this helps

Regards

Rob