first fault in 4.5 yrs

[bren999]

Guys. Started car after work tonight freezing temps ran fine for 10 miles then eml light came on drove another 6 miles home and switched off ,switched engine on again and rpm shot up to 2000 rpm blipping throttle brought it down again car ran as normal after eml came on. Any ideas? can't get it scanned until weekend

[kentphil1]

First things first, is the temp gauge staying at 90 degrees, or does it drop back?. When was the last time the throttle body was cleaned?. If both those questions answers are both satisfactory, then I would take a good look at the breather pipes. When it revs to 2000rpm, is it running cleanly or misfiring?.

[bren999]

Temp OK CTS replaced with green one a couple of yrs ago tb cleaned about 7 months ago running cleanly at all times thanks for your interest which breathers do I need to check please

[kentphil1]

Start with the "Y" pipe, then check the one's under the inlet manifold - will probably be the "s" pipe if it is down there. Was the CTS a genuine or aftermarket one?, as they supply input to the ecu for fuel injection metering as well as a gauge reading.

[bren999]

Was stamped as genuine bought it from a company called jorily automotive Skoda parts retailer will check pipes this morning and post results

[bren999]

Pipes seem OK been driving it today starts idles properly from cold and drives without fault only issue is hot start rpm goes to 2000 blipping throttle brings it down del light still on.I'm starting to suspect CTS as although its stamped with audi logo i cannot be certain its genuine it was changed 3 yr ago ,car has just turned 90k FSH from new inc 3rd belt and pump change.

[kentphil1]

When you get the car scanned will the person be using VCDS?, if so, get them to do a real time check on what the sensor is showing against the gauge

 

Difficult to advise further until you get a scan done really, as Lambda sensor can also cause these problems and bring up a cel.

[bren999]

Phil you were right scan showed fault on ECU signal from CTS 28 quid fix happy days. Thanks for advice