Only 26mpg. Lambda problem?
Discussion
Mixed driving, 30 mile comute on A, B and M roads only returns 26mpg on my MY01 2.3 Aero estate. I did some diagnosis at idle and got the following:
Would a new pre-cat O2 sensor improve things? Or should I start looking for other problems. No OBDII codes either. Thanks for any advice.
Would a new pre-cat O2 sensor improve things? Or should I start looking for other problems. No OBDII codes either. Thanks for any advice.
Cant see anything masively wrong with the data.
Fuel trim is the give away if somthing is running rich. Fuel trim should be between -5 and +5 maybe +-10 at a push 20% and you will get the engine management light on. The graph that shows long and short fuel trim on bank 1 sensor 1 look spot on. Between 0.7 and 2.3 is fine.
But if you get sothing like 99% thats got to be a read error, like that sensor isnt fitted to this model or more likely its a down stream sensor that is only there to check the cat is working and isnt involved in the closed loop for fuel trimming.
Can you reset any learned values with your diag kit?? might be worth trying that. If you can do any basic setting or calibration of the throttle body or EGR valve that can help too.
Fuel trim is the give away if somthing is running rich. Fuel trim should be between -5 and +5 maybe +-10 at a push 20% and you will get the engine management light on. The graph that shows long and short fuel trim on bank 1 sensor 1 look spot on. Between 0.7 and 2.3 is fine.
But if you get sothing like 99% thats got to be a read error, like that sensor isnt fitted to this model or more likely its a down stream sensor that is only there to check the cat is working and isnt involved in the closed loop for fuel trimming.
Can you reset any learned values with your diag kit?? might be worth trying that. If you can do any basic setting or calibration of the throttle body or EGR valve that can help too.
Gassing Station | Saab | Top of Page | What's New | My Stuff