Hello. Long time browser first time poster. Ok this may be quite a large post because i have been trying a lot of things in the past two months since i purchased my car but i'll try to be as brief as possible.
Brief history of the car .... its a 2001 Y reg A4 B6 1.8T with 126k. I bought it from a freind at work who has owned the car for 2 years. He said he had the head changed last year because it had a crack in it, the new head does not have an engine code where it is supposed to be so im not entirley sure of my engine model. The whole time he owned the car he had an engine light but the car always ran fine so he never looked into it. Im too ocd to have an engine light all the time so i immediatly started to investigate as soon as i purchased the car. I obtained VCDS and an ODBII bluetooth scanner. The car has 2 error codes. An ECU checksum error code that is continuosly pending (yellow) in torque app and never throws an engine light and a P0171 lean bank 1 code that is the bain of my life because i just cant get rid of it and it keeps coming back no matter what i do. I did a lot of searching into what causes the error and have tried to find the reason for it but have not been succesful. Please help...... here is what i have tried so far..
Changed pollen filter and installed K&N 57i CAI no change
Cleaned MAF sensor no change
The dipstick was broken and kept jumping out of its holder so i renewed it. No change
The fuel pump was groaning upon every start so i changed the fuel filter. It looked like the original filter and the fuel that came out of it was black so needed a change, the pump stopped groaning immediatly but P0171 returned
Next on my list was Vacuum leak , i inspected the hoses and found a 1" slice in the L shaped pipe that goes into the manifold so i ordered some silicone piping and replaced most of the vacuum hoses and check valves (except the one with the 3 outlets but it seemed to work fine under mouth test). I also replaced the pancake valve on the TIP. I cant see anymore obvious leaks and i can't hear any either........No change P0171 returned
Next i decided to do the " Squirt carb cleaner all over and listen for tickover change test" and found that it was getting in when i squirted it at the base of the injectors so i ordered an injector refurb kit from mr injector on ebay and changed the filters and top and bottom 'o'rings. No change.......P0171 returned
That just about brings me to current day.... im stuck. I don't know how accurate the Torque app is but it shows my vacuum as 24-25 Hg at tickover and my Boost at 12ish Psi during boost which i beleive is about normal for stock A4 so that makes me think it can't be a vacuum issue.
When i reset the error in VCDS the tickover goes a bit lumpy and then 033 measuring block "short term fuel trim"? goes up to 26% and tickover smooths out. I havnt hung around long enough to see what the 032 long term fuel trim goes to but i can if it helps anyone diagnose better for me.
Thats about it guys... Any recomendations as to what i can try next???
Cheers
Brief history of the car .... its a 2001 Y reg A4 B6 1.8T with 126k. I bought it from a freind at work who has owned the car for 2 years. He said he had the head changed last year because it had a crack in it, the new head does not have an engine code where it is supposed to be so im not entirley sure of my engine model. The whole time he owned the car he had an engine light but the car always ran fine so he never looked into it. Im too ocd to have an engine light all the time so i immediatly started to investigate as soon as i purchased the car. I obtained VCDS and an ODBII bluetooth scanner. The car has 2 error codes. An ECU checksum error code that is continuosly pending (yellow) in torque app and never throws an engine light and a P0171 lean bank 1 code that is the bain of my life because i just cant get rid of it and it keeps coming back no matter what i do. I did a lot of searching into what causes the error and have tried to find the reason for it but have not been succesful. Please help...... here is what i have tried so far..
Changed pollen filter and installed K&N 57i CAI no change
Cleaned MAF sensor no change
The dipstick was broken and kept jumping out of its holder so i renewed it. No change
The fuel pump was groaning upon every start so i changed the fuel filter. It looked like the original filter and the fuel that came out of it was black so needed a change, the pump stopped groaning immediatly but P0171 returned
Next on my list was Vacuum leak , i inspected the hoses and found a 1" slice in the L shaped pipe that goes into the manifold so i ordered some silicone piping and replaced most of the vacuum hoses and check valves (except the one with the 3 outlets but it seemed to work fine under mouth test). I also replaced the pancake valve on the TIP. I cant see anymore obvious leaks and i can't hear any either........No change P0171 returned
Next i decided to do the " Squirt carb cleaner all over and listen for tickover change test" and found that it was getting in when i squirted it at the base of the injectors so i ordered an injector refurb kit from mr injector on ebay and changed the filters and top and bottom 'o'rings. No change.......P0171 returned
That just about brings me to current day.... im stuck. I don't know how accurate the Torque app is but it shows my vacuum as 24-25 Hg at tickover and my Boost at 12ish Psi during boost which i beleive is about normal for stock A4 so that makes me think it can't be a vacuum issue.
When i reset the error in VCDS the tickover goes a bit lumpy and then 033 measuring block "short term fuel trim"? goes up to 26% and tickover smooths out. I havnt hung around long enough to see what the 032 long term fuel trim goes to but i can if it helps anyone diagnose better for me.
Thats about it guys... Any recomendations as to what i can try next???
Cheers
