Hudster Posted September 17, 2006 Report Share Posted September 17, 2006 I've had the following readings from my car, still can't diagnose the fault so any advice appreciated! 2 weeks ago I scanned and got: 2 Faults Found: 17536 - Fuel Trim: Bank 1 (Mult): System too Lean P1128 - 35-00 - - 17705 - Pressure drop between turbo and throttle valve (check DV) P1297 - 35-10 - Intermittent So I removed and cleaned the MAF with Isoclene Isopropanol. The car still feels the same (very uneven acceleration and little/no turbo at times) but now I have a different code coming up: 1 Fault Found: 17584 - Bank1: O2S (Lambda) Correction Behind Catalyst: Control Limit Reached P1176 - 35-00 - - Car is a 2001 1.8T Golf Mark IV with 62k on the clock Help Quote Link to comment Share on other sites More sharing options...
shark_90 Posted September 17, 2006 Report Share Posted September 17, 2006 I can't understand why you'd clean the MAF based on those fault codes, or you mean you did it anyway, not as a reaction to the codes? I don't know exactly what I'm talking about but as the O2 sensor measures emissions and alters the fuel mixture as part of the emission control system, perhaps a fault somewhere is causing the car to run lean? Quote Link to comment Share on other sites More sharing options...
slol Posted September 18, 2006 Report Share Posted September 18, 2006 Dan,you have had this fault for ages. The p1128 code is definitely a faulty maf and this will cause other problems,change this first, clear the other codes then take it from there. p1297 is usually a split hose,but you cant always detect the split unless the engine is under load Quote Link to comment Share on other sites More sharing options...
Hudster Posted September 18, 2006 Author Report Share Posted September 18, 2006 Hi Steve, it's been a while These aren't the same as the faults you scanned. I had a replacement pressure valve fitted and it cured the problem back in Feb. The faults in this thread appeared a few weeks ago. Happy to replace the MAF but don't want to do it unnecessarily - it's showing the correct readings in block 02. The general feeling is that it's a split hose, but I can't locate it Quote Link to comment Share on other sites More sharing options...
slol Posted September 19, 2006 Report Share Posted September 19, 2006 The (DV)diverter valve is also a possibility,usually referred to as the dump valve, but it works differently on vag cars. If you are logging block 2 are you doing this with the engine under load,ie flat out in 2nd gear? Quote Link to comment Share on other sites More sharing options...
Hudster Posted September 19, 2006 Author Report Share Posted September 19, 2006 Yea, it settles around 3 when idle, and reaches about 80 when accelerating flat out in 2nd, which seems to be right for that engine. There is a very subtle whistling noise if you have the windows down, which I assume is a hose or the DV releasing pressure / vacuum filling - but as yet I've not found a way of getting my head under the bonnet to locate it whilst having the engine under heavy load - revving in neutral doesnt cut it Quote Link to comment Share on other sites More sharing options...
slol Posted September 19, 2006 Report Share Posted September 19, 2006 Under full load the g/s reading should be about 120 for a 1.8t 150hp Quote Link to comment Share on other sites More sharing options...
slol Posted September 19, 2006 Report Share Posted September 19, 2006 Pasted from ross tech site, Here's a good sanity check for the status of your MAF. Do a full-throttle run all the way to redline in a single gear (second works fine). Group 002 usually shows air mass in g/s. Your peak airflow should be roughly 0.80 times your horsepower. So, if you have a stock 150 hp 1.8T, expect around 120 g/s. If you see significantly less than that, you MAF may be on the way out. Quote Link to comment Share on other sites More sharing options...
Hudster Posted September 19, 2006 Author Report Share Posted September 19, 2006 right, new MAF is on the shopping list, thanks for finding that Steve doesn't explain the hissing sound but as you said before, might be wise to get the MAF fixed and then diagnose any remaining faults Quote Link to comment Share on other sites More sharing options...
Hudster Posted September 19, 2006 Author Report Share Posted September 19, 2006 ...unless there's a VAC leak, in which case air would be sucked in and not be measured by the MAF, causing low readings Quote Link to comment Share on other sites More sharing options...
slol Posted September 19, 2006 Report Share Posted September 19, 2006 The fault is on the pressure side of the system after the turbo. The maf is non pressure,just after the air filter Quote Link to comment Share on other sites More sharing options...
Hudster Posted September 20, 2006 Author Report Share Posted September 20, 2006 new MAF ordered and on its way Quote Link to comment Share on other sites More sharing options...
AvantSE Posted October 5, 2007 Report Share Posted October 5, 2007 Resurrecting an old topic, but did the new MAF cure the first fault code you listed ? Had the same code come up on one of our A4s today. Quote Link to comment Share on other sites More sharing options...
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