Hi iv got a Audi 1.6 2008 petrol, more than a month ago my epc warning light come on, after getting diagnostics done my local garage told me I needed a new throttle body. So I brought a brand new throttle body from eBay matching my old throttle body part number. The day after the part was fitted I noticed my revs counter would jump up and down as if I was reving my engine when I was idle. This continued for a few weeks
Before the epc light returned, so took the car to a garage close to my work, they scanned the car and codes P1542 throttle valve position sensor 1 signal improbable and P1171 which is the same just sensor 2. Once codes where clear they told me they could not find a fault with the car. So a few days later the problem returns, this time I take it to a German specialist, they advise me it might be poor quality supermarket fuel and to switch to branded fuel. Few weeks later after emptying tank, car is worse as ever, epc light comes on regular sometimes with complete power loss, emissions light and esp light also come on now. Car will sound like its misfiring but the mechanic has told me this is not the case, idle will be really rough with revs counter bouncing up and down like made.

Car has since had v-power shell petrol filled to the top for a few days, error codes have been wiped, seemed better to start with, drove to work and back with no problems, Not sure if this means anything but when I got home I sat at idle and turn the a/c on and rev my engine and the epc light will come straight on everytime.

Any advise welcome

 

Having worked at a local small Oil Company that ran several different gas station with convenience stores several years ago, most gas is the same stuff regardless of where and how much you pay for it. We had Exxon, Shell, BP, and Chevron. They ALL came from the same trucks (different grades of course) from the same terminals. I don't think you have a gas problem.

You say you've replaced the Throttle Body, it's possible that something else needs to be reset or something did not get plugged up securely. Check the wiring harness in that area and make sure the connectors are not damaged an are tightly connected. Make sure any bolts or nuts on the sensors for the Throttle Body are tight as they can serve as ground for the electronics inside.

Unplug the connectors and looks to make sure there are no bent pins on them. Other than that, it's untelling what might be.

Try disconnecting the battery completely and let the car set for 24 hours as to reset the ECU and see what happens.