can a malfunctioning cam position sensor cause a backfire?

[RonPopeil]

just bought a mkIV gti. the guy i bought it from said he had to replace/rebuild the intake manifold because the motor backfired and went through the intake. i ran the codes and it comes up with a bad cam position sensor, secondary air pump and the O2 sensor looks a bit off though no codes for it.

does this sound legit or could there be something else going on?

btw, hi!

[GTIVRon]

Negative ghost rider. A bad cam sensor just retards timing by like 20*.

[RonPopeil]

well i've noticed that the car has a problem with cold starts. i'll turn the key and it will crank a bit and sometimes start and sometimes not. i have to cycle the key off and then attempt to start it again. usually, when this happens, it will be a weak start and takes a few seconds for the idle to level out.

i'm thinking there's a timing issue.

[Scotty_2.0]

Sound more like a coolant temp sensor failing. Does the exhaust smoke or smell like fuel?

[RonPopeil]

it doesn't smoke. haven't noticed excessive smell of fuel/richness. he has a magnaflow catback on it so it's hard to say.

would the coolant temp sensor throw a CEL? no codes for that one.

[Scotty_2.0]

would the coolant temp sensor throw a CEL? no codes for that one.

Not always, no.