Sluggish? 4.4 feels like 4 cylinder...FIXED!!
 

Thanks to everyone for helping me with the no start problem. That turned out to be the cam sensors.

It has poor acceleration that developed in the last month. I have already checked the fuel pressure static and while under a load. It is good (around 55 psi) and there is no leaking injector or anything. If I really get on it, it will set a code for misfire #8.

I've checked all the connections around the MAF and it is good. It idles perfectly. The plugs are new since the timing chain guide change. BTW it was running great after all that work so I don't think that's the problem. I swapped #8 and #6 coils and the misfire at WOT didn't follow it.

Once in the last week it set a bank 2 catalyst code but it had been idling for awhile and it hasn't come back. I noticed some oil in the spark plug hole for #8 so I cleaned that all out but no fix.
:dunno:

Anyone had this problem?

I'm getting a P0491 code which is secondary air injection system bank 1 insufficient flow.

Got rid of the P0491 code but now I'm getting a bank 1 catalyst code. Bizarre because before I got a bank 2 message.

I'm at a loss here.

I think there was another user on this board with a 4.4 that idled the car for about 45 minutes and then it drove sluggish. I forgot what his outcome was.

Possible catalytic converter? Restricting the flow and therefore reducing the power?

Can anybody pull that thread back up? It might help.

Couldn't hurt to swap the plugs. Just to rule that out, you know? Just to clarify, when you swapped the coils, you swapped coil + boot?

Is that a 76 or maybe a 757 flight deck I see?

I'm going to swap/check the plugs today and see what happens. It's so odd that it idles perfectly but plugs will make a fool of you sometimes. My Grand National plugs have to have a tight gap because at 25 psi boost, the spark "blows out" from the cylinder pressure.

Good call! That's a Continental Boeing 767-400. I always prefer being assigned to work on one of those than the 787's we have.

I'm going to swap/check the plugs today and see what happens. It's so odd that it idles perfectly but plugs will make a fool of you sometimes. My Grand National plugs have to have a tight gap because at 25 psi boost, the spark "blows out" from the cylinder pressure.

Good call! That's a Continental Boeing 767-400. I always prefer being assigned to work on one of those than the 787's we have.

Nope that's a 777-200 because the panel shows 14 tires and the next pic in my phone is the MAT terminal. I was doing a ground test I guess.

An idling engine may not get hot enough to start the catalytic convert working or hot enough to run efficiently. It may also load up the catalytic converter with fuel that could lead to an early demise of the catalytic converter.

There are tests that you can perform to determine if the converters are clogged. Look them up on Google or Youtube.

Alright. Swapped #8 and #5 spark plugs and still got a P1357 which is a #8 misfire. No other codes! Aaarrgghh!

When you floor it, it won't shift into 3rd gear because it won't rev up past 4000 rpm. If you let off the throttle a little, it shifts normally. Not a transmission problem just the engine isn't revving up under a load.

I think the consistent #8 misfire is just a symptom of another problem obviously. I'm leaning toward cats. I'll gut those things in a heartbeat and find some gadgets to fool the aft O2 sensors if need be.

Misfire could be due to bad coil, spark plug, injector, or low compression. Since you swapped the plug and the misfire is still in the same cylinder I would

1. Do a compression test of Cylinder 8
2. Swap the coil with another cylinder and see if the misfire doesn't travel with the coil.
3. see if the injector is working in cylinder 8. You can use a stethoscope to listen to the injector to see if it is clicking.

Engine won't rev under load, sounds like you got plug cats.

I believe if it were an injector, it would rev up past 4000rpm

Having the cats changed for $350 right now!

I'd like to thank everyone for their help!

It was the catalytic converters. I had a couple of universal cats installed and the old ones were broken up internally. It runs excellent now.

Can you edit the title in the original post to say FIXED so that other owners with a similar problem can find a solution.

Good to hear!