Hey everyone

I went to have a look at a used 2003 tahoe last night.

I was concerned about something when I test drove it though....
When I would put the pedal to the floor... it wasn't "all there" if ya know what I mean.

Im familiar with tahoes/5.3l performance and this one isnt JUST RIGHT.
The lady did mention that she just had the fuel pump replaced and the check engine light was on. She told me it was a Co2 sensor and that it would be replaced before I take the truck. Does this sound right ?? Would a bad sensor make the truck act this way ?

Other then that, the truck was great. It has 124,000 miles.

Thanks

 

Did it accelerate up to hwy speed and more OK. I don't mean hard with your foot in it just a normal pickup. Did it shift thru all the gears. My first thought was that maybe you were not in 1st gear taking off, that the tranny had not downshifted. My 04 Z71 has done that a few times. If you are really into the truck have her replace the sensor then test drive it again. If the co2 sensor is bad it may have caused the cat to plug up from running too rich and that would affect acceleration. Have someone stomp on the accelerator several time while you feel the exhaust with your hand. Compare to your car or one similar, not the last word but might give you an ideal. Another ideal is to have the fuel pressure checked, maybe the new pump ain't doing so good.

 

On my 91 chevy 4x4 it would go thru fuel filters every 25,000 miles lots of dirty Mexican gas I think. When the filter was bad it would only run up to about 2500 rpm then sputter and it did not accelerate hard, like it lost a few ponies. A new filter and everything was back to normal. It had the TBI system, not the seq. injection used today.

 

i agree about the dirty fuel filter, but on the other hand i had problems with o2 sensors, if thats bad it could be sending a bad signal to the ECU and making your engine run real lean, basiclly pooring gas into the engine. but if the service engine light is on you can go to most auto parts stores and they will check and see what code its reading and usually let you know the problem right then.

 

The girl Im buying it off of said her mechanic told her " its needs MAF sensor service and it needs a tune up "

So what does this mean ??? lots of $$$ ???

She said he couldnt do it for 2 weeks and im suppose to pick the truck up friday. The original deal was that she had the sensor fixed. So, I dont know what to do.

Her mechanic is her brother in law and I guess he never gave her an estimate because he is mad at her for selling the truck for to cheap.

 

I think you should have the codes read and see what they say first.

 

Ok so I ran the codes and i got 4 , one was the MAF , two were codes for bank one running lean and the other was a repeat code , the same as the bank one lean code.

I erased the codes and drove home .... 3.5 hours and the engine light didn't come on... EXCEPT when I punched it .... I was going about 10mph and put it to the floor , truck down shifted like usuall, but then had no *****. Also it ran up to about 6000-6500 rpm and I let off once I saw the engine lite flashing... Once I let off , the ligt stopped, and never came back on again .

Any thoughts ?

 

I think that could be your O2 sensors making your engine run lean. One could be bad making it read wrong and sending a wrong signal to your ECU.