P0300 and hesitation going up hills

[Rocket Man]

That’s some serious misfires imo. I don’t think it’s clogged cats but it could be I guess. I say you need a scanner that can show live data so you can see if there’s maybe 2 cylinders that are misfiring badly, it could be as simple as bad wires or coils. If you can narrow it down then you can swap parts around to see if the misfires follow. I had a couple wires that got burned inside the boot protectors because of my headers and my truck ran just like that. If you have wires that broke where they snap onto the plugs or they weren’t pushed all the way on they could be making bad contact. Sometimes it takes awhile for them to wiggle enough to lose contact. Just guessing here. It’s just easier if you can watch misfire data live. If you see it happening to all the cylinders then that’s a big clue towards fuel or cats.

 

[Meccanoble]

That’s some serious misfires imo. I don’t think it’s clogged cats but it could be I guess. I say you need a scanner that can show live data so you can see if there’s maybe 2 cylinders that are misfiring badly, it could be as simple as bad wires or coils. If you can narrow it down then you can swap parts around to see if the misfires follow. I had a couple wires that got burned inside the boot protectors because of my headers and my truck ran just like that. If you have wires that broke where they snap onto the plugs or they weren’t pushed all the way on they could be making bad contact. Sometimes it takes awhile for them to wiggle enough to lose contact. Just guessing here. It’s just easier if you can watch misfire data live. If you see it happening to all the cylinders then that’s a big clue towards fuel or cats.

I have the torque app. How would i test? I'll go back and make sure all is connected. They all show spark through spark tester. At one time i did get cylinder 5 misfire but same message hadn't come back since switching coils with cylinder 6

 

[Rocket Man]

I have the torque app. How would i test? I'll go back and make sure all is connected. They all show spark through spark tester. At one time i did get cylinder 5 misfire but same message hadn't come back since switching coils with cylinder 6

Can you see misfire data as the engine is running? I’m not familiar with the torque app. I use my Tech2 and can watch misfires for cylinders 1-8 and it counts them up to 100 cycles and then resets and starts over, and also shows history so if you sit there and watch for awhile it might do say 10 reps of 100 cycles and shows the total misfires for each plug which has fired 1000 times by then. If I’m getting more than a few misfires per 100 then something isn’t right. I was getting 20-40 per 100 on a couple cylinders.

 

[Meccanoble]

i dont remember seeing anything discussing misfires on torque

 

[kbuskill]

Can you see misfire data as the engine is running? I’m not familiar with the torque app. I use my Tech2 and can watch misfires for cylinders 1-8 and it counts them up to 100 cycles and then resets and starts over, and also shows history so if you sit there and watch for awhile it might do say 10 reps of 100 cycles and shows the total misfires for each plug which has fired 1000 times by then. If I’m getting more than a few misfires per 100 then something isn’t right. I was getting 20-40 per 100 on a couple cylinders.

Yes you can see misfires per cylinder with Torque Pro.

Personally I would pull at least 1 or 2 plugs just to put eyes on them and rule out it being a (fake) plug issue.

If the plugs look good then you can move on to looking at other possible culprits.

Thus is what my fake Delco Iridium plugs looked like when I pulled them compared to the new Ruthenium plugs...

 

[Meccanoble]

Yes you can see misfires per cylinder with Torque Pro.

Personally I would pull at least 1 or 2 plugs just to put eyes on them and rule out it being a (fake) plug issue.

If the plugs look good then you can move on to looking at other possible culprits.

Thus is what my fake Delco Iridium plugs looked like when I pulled them compared to the new Ruthenium plugs...
View attachment 249516

how many miles on those? Wouldnt i have issues a while ago, like within first 10k miles?

 

[kbuskill]

i dont remember seeing anything discussing misfires on torque

In the Torque Pro app go into Settings > Manage Extra PIDs/Sensors > press the 3 dots at top right of screen > select Add predefined set > Pontiac/GM/Opel/Vauxhall

Now scroll down about 40-45 PIDs and you will see this...


They are not in order... I don't know why... but all 8 cylinders are available.

 

[kbuskill]

how many miles on those? Wouldnt i have issues a while ago, like within first 10k miles?

Nope... mine had roughly 75k miles on them and I didn't have any misfires... only reason I changed them was because I wanted to try the Ruthenium plugs and I figured why not.

 

[Meccanoble]

In the Torque Pro app go into Settings > Manage Extra PIDs/Sensors > press the 3 dots at top right of screen > select Add predefined set > Pontiac/GM/Opel/Vauxhall

Now scroll down about 40-45 PIDs and you will see this...
View attachment 249517

They are not in order... I don't know why... but all 8 cylinders are available.

You are a God send. Great instructions except...mine only shows 6 cylinders. I have the free torque app. Not sure if that matters. It has 2 sets of misfires (current & history)

Also, what should be happening on this view? I can only edit or delete these options. They are set at 1000 max value.

 

[kbuskill]

You are a God send. Great instructions except...mine only shows 6 cylinders. I have the free torque app. Not sure if that matters. It has 2 sets of misfires (current & history)

Also, what should be happening on this view? I can only edit or delete these options. They are set at 1000 max value.

Once you enable the PIDs then you will want to go back out and go to Realtime Information and long press on a blank screen and Add Display then choose which type, I use the Digital Display then you scroll down,like you did before, until you see Misfire Cylinder (X) current or history and select the one you want to see. Do this for each cylinder.

I'm not sure why yours only shows 6 cylinders... maybe it is because you have the free version.