1998 single cab
2.5 5 speed

I've been getting alright gas mileage but I think it could be much better. Performance sucks! I've had the truck for a month or two. Did a full tune up. Plugs, wires, oil, filter-oil,air,fuel, Pcv...

The truck does not accelerate in 5th gear. Went to Dallas (4 hour drive) a week ago and on every hill I'd lose 10 MPH and that's at wot. The temp went up a little bit also. When accelerating anything over 3k the motor sounds like it wants to fall apart.

I got the solus out today and my O2mvs are reading crazy.
At an idle the upstream o2 jumps from 800, 730, 44, 0, 50, 250, 720, 30, 0, 800
At higher rpms the numbers are jumping around.

Downstream o2 is about 800 most of the time then drops to 30, 0 and back to 800.

Anyone seen this before?

 

Well just in case anyone is having the same problem..

I replaced both o2s and now the mvs do not drop to 0. The downstream does not move around. The upstream goes up and down from about 40-800 which I believe is cool.

I've only drove a little but I believe gas mileage is already better. Idle is smoother and doesn't shake as much when a/c kicks on and off.