I ended up taking my car to a shop for emissions and they said I would need a new MAP sensor because the readings where not correct. Same for the 02 sensor. The 02 sensor was pretty erratic when I was looking at it on a scan tool. The MAP sensor was at 1.58 Volts, new sensor is the same. This is too low according to a chart that I was looking at (3.8v - 5.5v).

I'm not sure what to do.'

Also, I saw that the hose going from the manifold to the sensor is just some 3/8" hose. This isn't right is it? I don't know if that would effect readings though.

 

On mine and all others I've seen, the hose is that black skinny plastic type with rubber fittings on the end. I think size matters here

 

I think so too. I found some of that vacuum line at the parts store and hooked it up. In drive the map sensor voltage is about 2.2v and over 4v while cruising.

Switched to my older o2 sensor and got readings that weren't so crazy, but this sensor is not heated.

 

The O2 sensor will constantly cycle from low to high(.200 to .900) if it and the fuel control system are working correctly. O2 voltage that hangs low, high, or center means either that the sensor is not at operating temp, the fuel control system is out of range, or that the sensor is bad. MAP voltage should be about 4.9 at atmosphere(KOEO) and range from 1.6 at idle(high manifold vacuum), to 4.5 at WOT(low manifold vacuum). MAP readings of over 5v will set a code 34 for MAP voltage high.

 

Yes thank you for the info. I got to learn this yesterday in class. There are a few leaks in my exhaust, one being right before the 02 sensor. This may be tricking the computer into seeing this as a lean mixture so I am putting the stock manifolds back on and checking it from there.

 

Yes, an exhaust leak upstream from the O2 can cause inaccurate sensor readings.