So my truck started running rough this am...haven't had any time to look at it...

Its running rough at idle...it's idling around 640 rpm +/- 15 rpm or so...

No codes...

Changed the plugs a month ago...new phasers and solenoids about 3 weeks ago...done about 1200 miles since the phasers...

Just looking at my scanner, the fuel trims are a bit fishy...the ltftrm on bank 2 is a -5.5, and all other numbers are a positive figure...

I'm not too happy...will probably have to start looking for a misfire...bank 2 looks like a good place to start...

 

Maybe you have the leaky injector issue? 2005 5.4, right?

 

5.4...the leaky injector thing is so hard to diagnose...I think it may be in the timing again...it runs good ad the rpm's increase...

 

Cleaned the MAF, and put a new fuel filter in it...no change...

It was due for the fuel filter anyway...

I think I am going to get it into the dealer...at least pay them an hour to hook it up and take a look...

 

If you have less than 120k and it's an injector, it shouldn't cost you anything.

 

That ship has passed...176K miles...

I would think I would be getting codes at this point...I have an Actron code reader/scanner...It doesn't show any...actual or pending...

I'm starting to think plugged exhaust system? I have had a bad drivers side cat for about 3 years...

After the phaser and solenoid repair truck ran good but I am getting a gas smell in the cab...could be bad fuel injector and it finished off the cat...

 

Truck is at the dealer...let's see what they come up with...I use the fleet department at my local dealer...they seem pretty good...

 

So, the dealer is saying low compression on cylinders 6,7 &8...

They didn't do an actual compression test ...this is what the computer is telling them....I guess it was the power balance test...the tech said he ran it several times...

The truck runs fine at speed...can do 80 on the freeway...

They are of course recomending a new engine...Its sitting at home now...I think I will get a compression tester and see what is going on...I am still thinking it's the Catalytic converter...plugged perhaps...

 

0That sounds good, but cat converters don't just "plug up". So, fix the cause, not the symptom. That compression check should come in handy, though.

On a side note, my old Ranger ran fine at highway speed, too. Even running on only three of four cylinders. It used gas like a ***** to do it, too.

 

Yes Alfred...I agree about the cat...It's been bad for about 3 years...P0430 codes for about 3 years...but it has given nothing to be able to diagnose the cause of the problem...the injectors would be the point of interest given the year...

Other than crappy gas mileage, the truck had run fine...no codes other than P0430...

It's not giving any codes now either...I am in the unfortunate situation of living in California (beautiful state, messed up laws)...there are no aftermarket catalytic converters that are legally available, so the repair is a $ 2,450 catalytic converter from Ford...add that to the cost of a new engine...

I am in the process of finding a good shop to take a look at the truck for a second opinion.

 

Leaky injectors may have plugged the converter and washed the oil off the cylinder walls and killed your engine. But, if you got 176k miles it's not all bad. If the converter is plugged, that may affect the compression readings, but should be consistent in all cylinders if all cylinders are in the same condition.

 

Had the Cats tested yesterday...they are free flowing...now to find a good shop to do a compression test...

 

Also pulled the throttle body and MAF sensor last night and cleaned them...didn't help any, but the throttle body sure needed cleaning...

 

So, I haven't gotten the truck in for a compression test yet...

I have been looking all over the internet for possible solutions other than a new engine...loose or cracked vacuum hoses and fittings and such...to no avail...

I gotta ask...where is this elusive hose that connects to the back of the intake that everyone mentions? I think it's described as going to the IWE system?

I realize that I am grasping at straws! I can't even afford the $ 350 for the compression test right now...believe it or not, it still hasn't thrown a code that my scanner can pick up...

Thanks to all that have already replied!

 

You are thinking of the PCV elbow, which yours doesn't have.