Air Intake Intercooler & MAP fault

[Guest fubar77]

Hello everyone,

Would appreciate your input on a weird problem which seems to be moving around from one error code to another.

Out of the blue after the engine check light had been on for a few hundred miles [!] the issues began - stalling at lights, cutting out as your driving, hesitation (as if an ignition fault). I connected a diagnostics to check the codes and it indicates a O2 Lambda sensor fault, as the issue. However somehow my A3 (8P1) hasn't got one fitted (maybe it has been deleted by previous owner, in any case I have driven around for 10,000 miles without it no problem). So i buy one and take try to fit it only to realise the sensor and it's wiring isn't there and no wiring for one is coming out of the ECU, so it's definately not in the system. On the drive back home, it then throws a blinking coil light symbol for the first time. So i get another diagnostic test done. This time it says Air Intake Temperature Sensor (the P0112 MAF Sensor just after the air filter), so I change it. Now it runs even worse but some things have stablised. A mechanic friend explained, it is the other Air Temperature Sensor (the MAP sensor at the intercooler end, the code says intimmitent problem), so i have that one replaced and the saga continues (rough idle, it stalled once and starts reluctantly but the idle is stable) plus some other improveimment, it has power but its still not right. Now its saying P0727 Engine Speed Input Circuit No Signal, P0652 Sensor Reference Voltage B Circuit Low, P2108 Throttle Actuator Control Module Performance.

This is the question: Someone has explained the entire issues are the result of ONE issue -a contaminated air intake circuit (intercooler etc) that it is saturated with oil and needs to be flushed out along with the DPF (which i am not sure my car has). I do have an minor oil leak btw. What do you think is going on. Could it be the ECU has lost its marbles?