Hey y’all, I needs some knowledge anybody that has any knowledge of the 99 4.2 are they a dog while driving? I’ve done a tune up besides wires gotta do that but when I’m going up a hill it just falls on its face. I’m running 245/75/16 I think I’ll double check n morning and its 2wd could it b the rear end gears or something else

 

The 2wd kind of looks like one as well.

 

My 98 4.2 does that, there's also quite a lot of knocking and pinging, fairly sure its the IMRC valves as per the code reader indicating P1537, P1538.

Throw a code reader on your OBD jack

 

My 4.2 is not a powerhouse, but it’s ok for what it is.

 

Mine seems sort of zippy off the line, must be low end torque doing that , perhaps the IMRC's change the
torque range with RPM / acceleration demand according to what I have read. Going up hills you can def see
a power loss, then the overdrive gear on the transmission engages to try and compensate for the loss of power
most the time, but if I try to blend into some fast moving traffic, I usually hear horns beeping at me, so I am hoping changing these
helps. Apparently if the vehicle sits a long time, the diaphrams in them dry rot and this one sat in a used car dealer for
12 yrs....theres also an occasional "tick" sound coming from the eng at idle, and I read thats another sign the IMRC's need replacing.

 

It does have a lean code on bank 1&2 (po171&po174) but would think that would b the issue but i guess it possibly could be the truck did sit for a bout a year before i bought it. Meen I’m not expecting fast like my 14 mustang but I’ve had a few v6 trucks and this just feels like a slug so didn’t know if the lean colds could cause it to b like that going up hills or if it was something completely different I needed to b lookin at

 

If you’re lean on both banks, you likely need isolator bolts and an intake mani gasket.

 

You need to hit the pedal harder then. Overdrive is definitely NOT designed to add power. If you are going uphill, click that OD OFF button and make use of the engine powerband. You won’t break speed records, but the horns will not honk behind you, either.

I have no issues with the occasional 4000 RPM blast up an on ramp if need be.

 

At 200hp 250 tq that's at the crank. So you're most likely running under 165hp. And 208 tq

Might as well call it a focus or a Chevy Cavalier or sunfire.

 

By default the OD button is off, the light on the control illuminates showing its off. I can hear the transmission doen-shift
up a hill when not moving too fast, so I assumed that was the overdrive kicking in?

By powerband you mean manually turn the shifter to 2 or 1?