What does Fuel Fail 23 VCM code mean on 1994 Jaguar XJ6?

Answer 1

There are several things to check most of the time you will need to replace the catalitic converter, this is common enough that the dealer still stocks the parts, also the upstream and down stream sensors must be calibrated after you replace the cat. BE VERY CAREFUL not to confuse the o2 sensors when thay are removed, Fuel Supply - Looks for poor feedback control in rich direction Could be O2 sensors - cat converter - or backfire caused - clear the error code and note if it recurs when a backfire or other exhaust event occurs. If a backfire or exhaust event causes the problem you need to fix the engine timing or other problem causing the back fire - a cat converter or O2 sensor can cause backfire.