KO4 fitted now have o2 and cps faults

[Robgti]

Long story short but had a full ko4 conversion done on my 2005 cupra.

Fitted a new pre cat o2 sensor as the kit was being fitted.

Had a few issues getting it to idle which turned out to be a leaky injector causing too much air to pass past the injector.

Now it starts up first time, idles high from cold as normal but when the revs drop it is idling a little rough.

It is showing fault codes P0130 and P0501.

I have also fitted a new cps sensor that i had bought a while ago to see if it would eliminate the P0501 fault but that hasn't worked.

I checked the connection box under the car last night hoping the o2 sensor was unplugged but it wasn't.

Now i can clear these faults but will be back as soon as i restart the car which is leading me to believe that there is no power or no signal coming from them which is weird as i would have thought if the cps was knackered then i would have trouble starting the car.

I use torque pro to monitor the car and have noticed that from the pre-cat o2 sensor there is absolutely no reading at all, the post cat reads very low at around 0.004v and there is no speedo display on the app which i think gets its reading from the cps.

I have checked fuse 43 and replaced just to be on the safe side which did not work.

Now i am wondering if there is anything that could be linking both of these faults together? Maybe they share a power wire or an earth.

Not sure if it is related but i am getting a can-bus error when trying to connect vcds via the obd2 port but my obd2 bluetooth dongle works.

Any help would be appreciated as i want to enjoy my car after spending £1000's on it lol.

 

[mty12345]

Hi mate. P0501 is related to the (VSS) roadspeed sensor (which i believe is screwed into the top of the gearbox) rather than the CPS. It could be the sensor itself failing, the wiring, or as you have had work done recently, it could just need reconnecting properly.

As for the P0130, if the sensor is new then i would suspect the wiring. Obviously where they are situated the wiring can get very hot, and as such can often get brittle. I would unplug the sensor and check the condition of the wiring, but a word of warning first, it is VERY easy to fry your ecu if that wiring gets shorted, so make sure you disconnect the battery just to be on the safe side.

Hope that is some help. Let us know how you get on.