+1 to O2 sensor going out...

Josh

 

I get 25.6 and I'm chipped. So there is something going on. When my EGT sensors and O2's were bad. my mileage was horrible.

 

I'm chipped i get around 21 - 22mpg and most of it is not highway. I guess there is hope for the S4 afterall. Are there any techniques other than replacing sensors that can increase gas mileage. And I'm not talking about keeping it under 2500rpms either.

Oh btw this isn't news to anyone here but still kinda interesting: http://money.cnn.com/2006/05/01/Auto..._mpg/index.htm

 

My 2000 S4 is Chipped and I get 26+ MPG. I am moving out of town and my commute to work which is 90% highway I push 28-29MPG.

 

+2 on the O2 sensors. just scan the car and let us know what codes u get.

 

Here's what I would check and or replace

- First get your car scanned for codes

- O2 Sensor (keep in mind we have 4 O2 Sensors). As stated before if they are still stock then it might be safe to replace them. They are expensive.

- Check your TBB (Throttle Body Boot) for leaks. Very common problem as we all know.

- Spark plugs

- Air Intake Filter

- Wheel Alignment (I always try to get a alignment every 6 months to a 1 year) FireStone has the lifetime alignment service for $150 some times cheaper.

- Tire Pressure

- Are you keeping your car clean? Interior and Exterior? Get rid of unneeded crap in your car.

- You are running premium gas right?

 

I'm chipped and get a consistent 18 mpg city with moderate driving. That's in line with the manufacturer estimate and the car runs fine. If I went heavy, I'd be getting 16 mpg....

 

Grr.. Cant get my post to go through

 

Thanks to everyone for your responses. I FINALLY had a little free time to take in into the shop.. When scanned its coming up with a P0170 code.

Also it appears that it has never had any major service done to it so I'm hav-ing the drive and timing belts, water pump, thermostat, oil filter, spark plugs, fuel filter and vacuum hoses and valve cover gasket replaced. (The air filter is a brand new K&N)

One mechanic suggested replacing the air flow meter and oxygen sensor but I think I will start with the service then go to the oxygen sensor if the service doesnt help the situation.

My question is: if the oxygen sensor or air flow meter was malfuctioning/not working properly wouldnt the check engine light come on?

Also, was the mechanic jumping the gun by wanting to replace those two items along with everything else with out checking to see if the service items fix the problem first?

The service is already costing me $2000. The oxygen sensor and air flow meter will be another $800. I'm trying to minimize the damage to my pocket here

P.S. Car is clean, Tire pressure is good, and yes, premium gas.

 

So I found the problem to why I cant post.. For some reason that I can not understand it wont let me post the word "hav-ing" with out the "-"