Truck seems to like 1st gear too much

[screaminchicken]

My truck seems to lose power and stay in first gear too long and it struggles to get to the upper rpms. The SES light flashes after I hear pinging but the pinging sound has been there ever since I can remember unless it runs with premium. I once had a knock sensor code that came on but then went away back when it had 57,000 now its at 84,000. After the light flashes the convertor wont lock up for awhile. I changed plugs to the NGK TR6's and MSD wires and it seemed to go away for awhile. I hooked my friends Snap On Ethos to it and it showed quite a few misfires on cylinders 1 and 2 or 3 I think. And when I rev it up high in park and it goes back down to idle you can feel it misfire badly. ANNNDD the exhaust kind of has a fluttering noise from it. SOOOO...... Is it my coil packs, knock sensors, catalytic converters (which I'm going to gut out soon) or something with fuel or what? I want a second opinion before i start spending money. Thanks in advance.

[tanz45]

Pull out the front 02's and see if it will rev out. If so, then the kittens are clogged.

Flashing SES light indicates damage is occuring to emissions systems

[RedHeartbeat]

You could start with new knock sensors and harness and then add new ls6 valve springs if the cats arent clogged.

Also check the fuel pressure.

[screaminchicken]

You could start with new knock sensors and harness and then add new ls6 valve springs if the cats arent clogged.

Also check the fuel pressure.

Would the LS6 springs actually benefit a stock motor? I'm not going to do anything with this motor also, I just bought a 6.0 that will be twin turboed

[RedHeartbeat]

The main thing about replacing the springs is that you will be getting new strong springs on the heads that will eliminate any potential of weak or floating valves that you may currently be facing. The added bonus is that they are about $60 a set from SDPARTS.COM.

[96/chevy/pu]

What about starting with a fuel filter

BB

[screaminchicken]

It doesn't rev past 5,800 and it has 84,000 miles I don't think that the springs would be a problem but I'm not sure. And I have just recently changed plugs, wires, fuel filter, cleaned TB and intake and did seafoam but the problem was before all of that and didn't change after a tune up.

[RedHeartbeat]

uh, have you ever thought that maybe your rev limiter is set to 5800 in the tune? BTW, much more than 5800 and you may start bouncing the valves with the stock springs.

[screaminchicken]

uh, have you ever thought that maybe your rev limiter is set to 5800 in the tune? BTW, much more than 5800 and you may start bouncing the valves with the stock springs.

I have no tune the motor is stock like I said before. Down to the paper filter it's bone stock. The limiter is at 6,000 and it shifts around 5,500.

[RUFFNECK]

Sounds like it is pulling timing for some reason. Mine does this but its becuz I put in a cam so the noisy valve train is triggering the knock sensors(i think). Bad gas usually causes pinging. But it also sounds like you may have some weak coils. Change out the fuel filter to see if it helps any.