This evening I was driving on the high way speed limit was 70 and my truck just could get it up their. ( the winds were very strong but still I was going 65 but it wouldn't go 70 also the petal is very stiff and hard to push down at 65 mph ) so I turn O/D off and the truck clims like it should no problem at all the petal is no longer stiff/hard to push. Also when I was going 65 and would try and mash the petal and wot the Rpms would jump from about 2100 to 3000, I've spent the last hour reading threads on here and can't find a answer, possible tv cable? Fuse? Alternator ground? Lead on battery? I should also note that with the past three months I had a tranny shop replaces the gov pressure fulid and filter, the only other thing I can think of is their is a hose with a vent type cap hanging from the rear of the truck but it has been for two years and when I worked at Nissan the mechcanics their said it was just a vent hose, any ideas? I have a week break next week so I can tackle some of these problems I've been having, thanks for any help!

 

Plenum been done? Hows the cat? O2 sensors?

Just turning off O/D should have zero effect on your throttle. It's just electronic wizardry. Verify that the throttle cable is routed correctly, and isn't binding. Do the same for the TV cable.

Lack of power in O/D isn't all too terribly unusual, but, can be an indicator of blown plenum. Tromping down the the gas pedal does two things, biggest of which is, trans downshifts. next is, PCM goes into open loop, and ignores the O2 sensors. If the truck has plenty of power at larger throttle openings, but, is a dog with somewhat less agressive driving, replace the O2 sensor, (pre-cat) and reset the PCM. See if that doesn't improve its attitude at all.

 

Pre cat 02 is on the list of things to do and plenum was fixed 2 months ago, I could pull the pre cat sensor run up the highway and see if that makes a difference but it will still throw a code correct since it will be disconnected, right?

 

I agree with HeyYou on the throttle. And turning the o/d off only allow you go from 4th to 3rd. If you are having lack of power then the exhaust maybe plugged.

 

Alright I will see if I can get it scanned before I put a new 02 sensor on their but i bet It needs one after the plenum was leaking for so long.

 

Highly likely. Mine looked horrid when I pulled 'em. Truck ran better with a new one.

 

I got it scanned nothing came up, but was recommend a tps sensor it was replaced before the plenum was done though. I'm still going to change the o2 sensor has anyone bought anything from rock auto?

 

Lots of folks. They are actually pretty good. I haven't seen any complaints here about them.

 

I bought my latest o2 from there. Can't beat a denso OEM replacement for 25.99 shipped.

 

+1 on the above, bought several items from them, have a Denso O2 sensor on it's way as we speak. No complaints here.
Go to the last page in the Rock Auto Discount thread in the non tech section for a discount code before ordering. Type it in where it says "where did you here about us".