1999 S70 T5 - LTFT high Topic is solved

[jimmy57]

A positive LTFT indicates ECU is adding fuel, so you still have a leak somewhere or MAF over-reports. Leak can be anywhere after MAF, all the way to just before sensor in the exhaust. Look at STFT at idle, should be positive at idle as well, if it declines with revs then it's a leak.
More boost than normal will create a similar condition, can your scanner read boost?
If you post MAF readings perhaps someone else, having a good running similar car, can post his for comparison.
Any codes yet, freeze frames?

If MAF over-reports then LTFT will be negative value indicating the ECM has taken away fuel. Air leaks before turbo causing UNDER-reporting MAF will result in lean indication from O2 sensor and then STFT will go up in value as a temporary multiplier increase from base computation and then ECM will bump up LTFT until STFT goes back to its normal range. Assuming the LTFT doesn't go to its 25% limit. That limit can be higher on some models.

Here is a decent explanation: http://www.easterncatalytic.com/educati ... stic-tool/

[kallekula]

OK, haven't had much time lately to look at the car until now.
Checked fuel pressure, vacuum leaks and compression. Everything within spec. Exhaust gases smells like an old chevy 57.

I have VIDA but I'm still kind of a newb and don't know how to use it properly yet. Here are some values I read at different rpms (car in Park all the time). I noted that the parameter "ECM-Long-term fuel trim lower part load, bank 1" doesn't contain any value. Also, rear O2 sensor output is jumping up and down, is that normal?
What can be concluded looking at these printouts?

[draser]

Oxygen sensors seem to read fine, with front slightly rich at idle then stuck on 1, so it's right at center of range. Rear will switch but less than front one, and if there's no cat efficiency fault it's fine. Now the MAF: idle value seems okay, hopefully someone with similar engine will confirm. The way reading increases with rpm shows good air flow, hence cat not clogged. Would be nice to have engine load readings as well. The fact that fuel trim goes down some with revvs, from previous post, points to clogged injectors.

[misha]

Usually,when rear o2 sensor reading jumps up & down just like front o2 should do,it means that cat is not doing it's job.
Rear o2 sensor graphic reading should be steady with very little to no movement at all,if cat is doing it's job.
If you're getting exhaust fumes smell just like old cars have...that is your answer.Old cars don't have cats and if yours doesn't do it's job....it's like you don't have it either.

Good working cat,when engine is running rich,produce a rotten egg smell.

[kallekula]

OK, this car is starting to drive me nuts. This is the current situation:

1) New catalytic converter
2) No intake leaks
3) No exhaust leaks
4) New MAF that reads around 4.5 g/s on idle (same as old one)
5) Fuel pressure steady at 57 psi both when idling and when driving

Still, the longer I drive the car the more LTFT goes up. It's now at + 24% indicating too much air/too little fuel.

I would really appreciate if someone could help me sort this POS car out. I have Vida/DICE, what parameters should I monitor and under what condition(s) ? gahhhh

[dan_t]

Did you ever get to solving the issue with this? I'm having similar problems.

[kallekula]

Yes, wrong injectors that didn't flow enough.