Engine bog

[Red jack]

So the last few days I have been experiencing engine bog, in 3rd or 4th gear the engine has horrible bog at 1/4 throttle if I downshift to 2nd gear but hold the thrattle at 1/4 throttle it still bogs as I slowly push the pedal it remains until about half throttle it starts to pull like normal again but I don't know what's wrong or how to fix it. I suspect egr valve or fueling issue but I'm not sure. Any help is appreciated

 

[skylark]

I'm going to guess that your truck is a tbi. You need to do a fuel pressure check. Unfortunately with tbi there isn't a test port so you will need to rent or buy one that has the tbi adapter. Your fuel pressure should be 9-13psi but make sure that you are checking it while you are driving.

 

[Red jack]

I'm going to guess that your truck is a tbi. You need to do a fuel pressure check. Unfortunately with tbi there isn't a test port so you will need to rent or buy one that has the tbi adapter. Your fuel pressure should be 9-13psi but make sure that you are checking it while you are driving.

Yes, sorry my truck is a 5.7 l tbi it has a heated o2.

 

[jkeaton]

Check engine light on?

 

[Red jack]

Check engine light on?

The check engine light does come on but it's not constantly on like sometimes I take a corner and it will come on.

 

[jkeaton]

Scan for stored codes. Might be useful.

 

[Red jack]

It has a code 43 which from what I've read has to do with the knock sensor.

 

[ram1220]

Had this in my 90 Sierra 5.7l TBI a few years ago. Was turning on the CEL only on the highway. I changed the EGR, O2 sensor, and fuel filter. Problem was gone after that.

 

[1995sierraz71]

I had the problem with my 95 350 tbi. Mine ended up being a throttle position sensor (tps)

 

[SLmateo]

Check your fuel pressure. I replaced alot and then checked... new fuel pump and is good now... would have saved some money