On Fri, Dec 4, 2009 at 3:30 PM, Michael Hart <mjhart853@yahoo.com> wrote:
> My '97 Jetta GLX (VR6) [120k miles] keeps getting check engine lights, causing the car to fail CA SMOG (although the emissions are completely normal). The codes are
> P0171 Fuel Trim, Bank1 System too Lean
> P1128 Long Term Fuel Trim Mult., Bank1 System too Lean
> P0440 EVAP Emission Contr.Sys. Malfunction
>
> The car runs fine (of course) but I can't figure out what (next) to fix. I've checked the web for this & find many possibilities. I've replaced the Air Flow Sensor, checked for vacuum leaks, replaced air filter, plugs, cleaned all air inlet pies & boxes, all with with no improvement. Anybody seen this and have suggestions?

If you haven't already, search those codes on the vortex VR forum

http://forums.vwvortex.com/zeroforum?id=29

As for the EVAP, I bet your system uses a LDP (leak detection pump) It
pressurizes the system from time to time to check for leaks in the
EVAP system. A timer relay closes the evaporative canister condensate
drain valve and ECU tells EVAP purge valve to close when pump on. If
there's a leak, a code is thrown.

Bentley says basic checks begin with visual inspection of the evap
system hoses, components..... fuel cap and seal.

If you can get your hands on an A3 Bentley, read through section 20.

Neil.

-- 
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines