So I have an 02 blazer 4 door 4wd and when I get up to about 45-50 it feels like it bogs down and it sits steady at 1500 rpms and won't move untill I put my foot down almost to the floor. But as soon as I let off it kicks right back to 1500. I'm thinking it may be a Transmission issue because I know that the 4l60E isn't the best transmission, but I've also been told a few other things and I figured if anyone knew the problem or how to solve it, it would be you guys. Any help is much appreciated.

 

So it tops out at 1500 rpm or it bogs down lower than that when you try to accelerate?

Do you have any codes?

Can you read live data with a capable scanner?


George

 

It feels like it bogs down. It'll jump out after I hit 55. But it just sticks at 1500. And while ots sticking at 1500 I can still accelerate but the rpms stay steady. I have a code reader but haven't tried running live data. (I will now, thanks for the idea by the way) I used to have a code come up for my Trans. But it's been a couple months and 3000 miles later. If it helps I'll give you a little back story on my blazer. Before I bought it it belonged to one of my buddies grandma and they parked it In a field for a few years ago after she took it to a shop for apparently a blown head gasket. It had a lifter tick on cylinder 4 but I fixed that. Injectors, fuel pump and filter were clogged, Replaced those. And after I bought it I did an oil and filter change as well as changed ghe tranny fluid, filter and gasket. I'm missing an o2 sensor because the cats got cut off so my exhaust is just kind of Jerry rigged on there.

 

So the truck will increase in speed but the rpm’s don’t change?

What does bogs down mean? You press the accelerator and the truck slows down or you press the accelerator and the speed will not increase?

What transmission code did you have?

Which O2 sensor is missing?


George

 

It'll increase in speed but rpms won't change untill I get to about 55 then the rpms aren't sticky. The Trans code was p1870 transmission component slipping. And when I say bogging down it just sounds and feels like there's more resistance pulling me backwards if that makes sense. Luke the truck is trying harder to stay at the steady speed. And it does it both in and out of cruise Control. And the o2 sensor that's missing is the on directly under the passenger seat

 

There are (were) 2 precat O2 sensors, one in each bank. Apparently you no longer have B2S1. Those control fuel delivery by monitoring the air/fuel mix in the exhaust. If you have a working sensor in bank one and a missing sensor in bank 2 then fuel control is messed up. In the absence of a working sensor the system cannot go into closed loop fuel control and has to rely on many of the other sensors to compute the injector pulse width (amount of injected fuel). Any one of those sensors (MAP, MAF, ECT, TPS, ...can be having problems as well as the air intake, vacuum, fuel injectors, etc. One of the benefits of the O2 sensors besides lower emissions is that they can compensate to a certain extent for problems in these sensors/systems. This also removes one of the best tools for diagnosing problems, fuel trims in live data. Your best best is to have the exhaust modified to accept this missing sensor. If thats not possible then the truck may run better with the other one unplugged, not sure on that one. Lastly, you will have to check the health of all of the other sensors with live data, rule out any vacuum leaks and test the fuel system. I would test fuel pressure and leak down first.

That transmission code is serious and indicates slippage in the drivetrain. Here is a blurb on that issue:

https://www.motor.com/magazine-summa...870-june-2006/


Let me know if I can help with any testing.


George