UK Car Repair Questions? Ask a Mechanic for Answers ASAP
Hopefully i can help.
If the fualt isn't effecting the car in any way and seems to still perform well even with the EML/check engine light on? then there won't generally be much you can check visually or repair at this stage around the engine bay itself unless the fault is actually effecting performance in some noticable way and even then would likly still require a suitable diagnostic machine to retrive the "P" fault codes from your cars ECU to get at least a clearer or better idea which sensor / electrical component / plug,wiring on the car is actually being picked up as faulty by your ECU "hence the reason for your engine light coming on" and to where to start making the further checks or replacements with fualts like this it can be quite difficult to pin point it to a specific area as this warning light can cover quite huge area of possible fualts...You can however make a check around engine bay making sure a electrical multiplug connections/wiring for any damage and are secure etc around the engine plus to check all vaccum/intake hoses are secure and don't show signs of any cracks or splits.also have the engine running to see if you can hear anything or spot any problems that way.or check up on a previous "recent" work carried out and checks these areas too..Sometimes it can be a simple glitch picked up by the ECU and once the fualt memory is cleared sometimes won't return..