problems and need some advice

[monty-bob]

hello to all,


im looking for some advice with the few problems im having with my 2001 S3. this will be a long story so bear with me.


ive just bought this car from a local garage and within the 1st week the exhaust ended up with a hole in it by the 2nd lambda sensor, and the engine management light came on. assumed the 2 were linked together as it came up with the fault code

(PO171 SYSTEM TO LEAN BANK 1)


garage took the car back in, welded the exhaust and all was good. next day engine management light back on. same fault appeared as above.

garage took the car back in and changed the engine temperature sensor and gave me the car back. all was good again until yesterday when the engine management light came back on again.

ive scanned the car with my reader again and now its coming up with 2 faults -

(PO171 SYSTEM TO LEAN BANK 1)

(P1296) unsure of this fault , any idea`s ?

ive phoned the garage and told them the fault is back with a new one also.

they are now telling me because the car has had a stage 1 tune its probably the problem. this sounds like utter pish to me as there are many higher tuned cars out there with no problems like this. they say the car is probably gonna have to get put back to standard.

i do not want this to happen as i dont think this is the problem and i dont want it to be slower. it sounds like a get out clause to me.

does anybody have any idea`s to the above problems and could point me in the right direction.

thanks in advance

steve

 

[Gops]

16555/P0171/000369 - Fuel Trim; Bank 1: System Too Lean


Possible Causes
Mass Air Flow Sensor (G70) defective
Intake System Leak(s)
Possible Solutions
Check Mass Air Flow Sensor (G70)
Check Fuel Pressure Regulation
Check Fuel Pump
Check Injectors
Check Intake System for Leaks
Check Exhaust System for Leaks
Check Secondary Air System for Leaks
Check Vacuum Pipes for Leaks

17704/P1296/004758 - Error in Mapped Cooling System
Possible Symptoms
Cold start issues
Possible Causes
Coolant Temperature Sensor (G62) faulty
Coolant Thermostat faulty
Possible Solutions
Check Coolant Temperature Sensor (G62)
Check Coolant Thermostat
Special Notes
Check the stored Freeze Frame data with this fault code. Freeze Frame information will be found in the fault code description (if the module supports it) or in Generic OBD-II if the vehicle complies with those regulations.
Freeze Frame data stored at -40 °C is generally an indication of a faulty ECT or wiring.
Freeze Frame data stored at +140 °C is generally an indication of a faulty ECT or wiring.
Freeze Frame data stored with in the 60-80 °C range is an indication that the vehicle was close to, but not within, the cooling systems normal operation range. The Thermostat itself or Cooling system components may be at fault.


Thats from Ross tech. Check your maf for the first code. 2nd one you said you changed the temp sensor? Might be the thermostat itself.

 

[monty-bob]

the fault code P1296 came on for the 1st time last night which would be the temp sensor section. the garage has changed this temp sensor for some reason thinking it was solving code PO171. which in turn has made a new fault (P1296) which was never there before.

where is the temp sensor located as ill have a poke around at it?

how do i check if the maf is faulty then? i think i know where it is. on top of the boost pipe?

thanks

 

[ex911driver]

Maf will be connected to the pipe in front of airbox, disconnect it and if it drives the same it has had it.

 

[monty-bob]

Maf will be connected to the pipe in front of airbox, disconnect it and if it drives the same it has had it.

The car drives fine just now so i take it once disconnected it will drive crap

 

[<tuffty/>]

A too lean code is more typically to do with a vacuum leak... check all the pipes under the inlet manifold... if there is oil everywhere then it normally indicates a split pipe and oil is getting blown out under boost... under vacuum it will suck in unmetered air that the ECU compensates for by adding fuel... when the trims go +25% then you get a CEL and a fault code

Normally its a fairly big split to throw a lean code...

<tuffty/>

 

[monty-bob]

Maf will be connected to the pipe in front of airbox, disconnect it and if it drives the same it has had it.

ok tried this and car didnt drive any different. so assuming maf is gubbed then. only difference i could see was a new fault code.

 

[monty-bob]

A too lean code is more typically to do with a vacuum leak... check all the pipes under the inlet manifold... if there is oil everywhere then it normally indicates a split pipe and oil is getting blown out under boost... under vacuum it will suck in unmetered air that the ECU compensates for by adding fuel... when the trims go +25% then you get a CEL and a fault code

Normally its a fairly big split to throw a lean code...

<tuffty/>

there`s no leaks anywhere that ive noticed but never really been looking for that . ill have to look for split pipes tomorrow . cheers

 

[Gops]

Temp sensor is on the right side of the bay. You'll see the temp sensor housing as all these water pipes lead to it.

ive just realised tuffty that I've still got the same housing from bills drag car from when my car did a wee on the dyno lol! Holds up nicely that means my car has an extra 30bhp. Haha