89 SHO Lack of power

[jatsie]

Hello, I have an 89 SHO that seems to have a lack of power when I floor it. If I very slowly roll into the throttle, it seems to do better. My first thought was a plugged cat, so I removed the O2 sensor to check the back pressure. The back pressure was zero, but I did notice that the car ran great with the 02 sensor disconnected. I replaced both 02 sensors, but still have the same problem - seems to run great with 02 disconnected. Any thoughts?

 

[SHOdded]

Possibly needs TPS replacement, doesn't throw a code when bad. Tried running the car with the MAF plugged in vs unplugged?

 

[rubydist]

did you actually check for codes, or are we just guessing there are none?

 

[jatsie]

I have not checked for codes yet. The check engine light has not come on, so I figured there would not be any codes. I will check for codes. Should I just check with the engine off?

 

[Irish Pride]

Run both tests and see what comes back.

 

[rubydist]

assuming there are not codes because the check engine light is not on is like assuming your wife is dead because her eyes are closed - its possible, but unlikely.

 

[SHOdded]

assuming there are not codes because the check engine light is not on is like assuming your wife is dead because her eyes are closed - its possible, but unlikely.

LOL. Yeah, you'd think all codes would be stored and the driver would be warned with the CEL, but I guess then too many CELs might be thrown

 

[ISHOU]

I've wondered lately how far out of range until a CEL goes on. I've had two performance problems the last few years, bad MAF and DIS, and neither turned the light on but did leave a stored code.