SilverVRSex 0 Posted July 26, 2010 Report Share Posted July 26, 2010 I have a 99.5 Jetta VR6 that has been having some problems when starting. I've only had the car a few weeks and I've been trying to get the car running as good as possible. Anyway the problem I'm having is when starting the car the car revs itself up and down and sometimes stalls as soon as I start it. It only does this if the car hasn't been started for a few hours. The problem started yesterday after I replaced the spark plugs. The plugs that were in the car before were single electrode snd the new ones are the dual electrodes that ngk recommends...can't remember the part number off the top of my head.The car used to rev itself sometimes when shifting from 1st to 2nd but the new plugs fixed that. When I was changing the plugs 2 of the rubber boots on the wire that connect to the metal piece that goes in behind the plug came out so they are just pushed back in for now. Could that be the cause of the problem? I'm ordering new wires either way but it would be nice to know if that could be the problem or if its probably something completely different. Thanks for any help...I'm new to vws haha. Link to post Share on other sites
SilverVRSex 0 Posted July 27, 2010 Author Report Share Posted July 27, 2010 Took my car and had the check engine codes scanned. Came up with P0134 Heated o2 sensor bank 1 sensor 1 sensor circuit no activity detected. P0304 cylinder 4 misfire. And P1240 injector circuit open cylinder 4. I got some wires while I was there too and changed them out. Not sure if it helped yet though wont know til I try to start it tomorrow. How could changing the plugs really cause all those problems? Link to post Share on other sites
SilverVRSex 0 Posted July 27, 2010 Author Report Share Posted July 27, 2010 Anybody have any help to offer? Im experienced working on cars but mainly performance modifications. Havent done much as far as diagnosing and fixing problems because well...my other car was a Honda. Link to post Share on other sites
gavinvr6 0 Posted July 27, 2010 Report Share Posted July 27, 2010 p0304 and p1240 sounds like the the same thing, possibly the injector playing up causing a mis-fire on no 4 cylinder. not sure what heated o2 sensor is could be the lambda. ive only ever used a generic hand held fault code reader not vag-com and those codes dont match my handhelds list as it uses its own codes/descriptions Link to post Share on other sites
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