need some help with a problem i noticed today
changed my tranny fluid today with royal purple synchromax
shifted smooth and everything
but later that night i was messing around and under hard throttle in 1st and 2nd gear
the truck bucks and jerks, like it will jump to 2k, then down to 1.5 then up and down
under smooth throttle its ok
no noises or anything abnormal
also i dont know if this would be a cause
but my ses light came on last week because of an 02 sensor with low voltage
i replaced the one after the cat but the light is still on

 

I doubt that changing the transmission fluid had anything to do with your new found problem.

What was the specific code you received?

 

i have not checked the code since i got this problem
but when the SES light came on last week the autozone guy said i had low voltage in an o2 sensor
i was thinking that it could also be some bad gas?

 

Bad gas is a possibility. You could try some IsoHeat into the tank which would take care of any water that might have made it into the tank.

Do you remember the specific code (Pxxxx)? That will point you/us in the right direction for getting the code repaired.

 

no the guy didnt show me the codes, just told me what was wrong
we replaced the cap and rotor today, made a little improvement, not much though
i dont think its ever had a tune up in 74k miles
i think my dads going to take it to the dealership

 

I had an issue like this before after I had a tranny flush.

I have a theory behind it. When I did a tranny flush on both of my Blazers, I would get a strange jerk while I would drive. It was only temporary(~a day or two.)

Anyways, this might sound crazy, but I think what happens is the fluid isn't fully circulated through the transmission, so you get slippage because some areas are starved of fluid. Like I said, it happened to me twice after a transmission flush, and was very temporary, but inconvenient. If it happens to you you for more than a couple days, I would get worried.

 

well my dads taking it to a mechanic who works on my sisters honda
he used to work for gm
and has a shop at his house
he works on imports on the side so he should be able to figure this out

oh and as far as i can tell this only happens between 2 and 3 thousand rpm
it seems to stop after 3k

*update- on the way to the shop, the ses light went off and my problem dissappeared
this was all highway driving
hes going to drive it and see if he can make it act up again
might need a new fuel pump from what im hearing

 

well good news. the guy scanned everything, checked it all over, and nothing is wrong
turned out to be that faulty o2 sensor telling my computer my truck was running rich. so when i gave it full throttle, it was cutting back on fuel. but i got the o2 sensor replaced and im getting my baby back tomorrow

 

Sounds good. Let us know either way.

 

well it runs even better now, since i changed the cap and rotor
still trying to figure out my abs, ebrake, light and my speedometer not working problem ive had a few times
seems like it happens every time i unplug the battery
im in the process of checking all grounds
sometimes it gets fixed by unplugging the abs unit and plugging it back in
fixed it this morning but it came back
seems to pop on or off when you go over a railroad track or something like that etc.