I have a '97 F150 with the 4.6L that has a clogged passenger side cat. The truck was running rough and I put it on a scanner, which showed a misfire in cylinders 3 and 4. I did plugs and wires (the boot on the wire for #4 was pretty bad), hoping to help the problem. It kept coming back, so I checked the coil pack, which I noticed was cracked right where the plug on the side comes in. Still, the cylinder #4 misfire kept coming back, and now a low efficiency on the cat for bank #1.

The truck has 206k miles on it, and I really don't want to drop $400-500 on having an exhaust shop replace both cats on that side.

Any suggestions? Do any of the universal cats out there work ok? What about dropping the exhaust myself and gutting the cats? I'm looking for the lowest cost alternative. I almost wonder if an exhaust shop would cut out the cat and put in a straight pipe, since I don't have emissions testing and it's a 11 year old truck.

With having over 200k miles, the only thing I'm concerned about is making sure it runs fairly smooth, and I'd like to get another 25-40k out of it. The truck looks and runs great otherwise.

 

Gut the cat and get some MIL eliminators

If you live somewhere where they do emissions testing, then I would look into the aftermarket hi-flow cat's and just put one on each side. I hear that Magniflow makes some pretty good units:

http://www.car-sound.com/

http://www.car-sound.com/02product/s...F%2D150+Pickup

 

I do not have emissions testing where I live. So at least I have that going for me.

 

It sounds to me like you still have the stock exhaust muffler on the truck...so if you do end up gutting the cats, it wont be loud (unless you want loud )....

Gutting the cats is technically "illegal", but it's free, and you'll never have to worry about them clogging again.

 

Actually, my brother had the truck before me and did replace the muffler 50-60k miles ago with a cheap Dynomax muffler. I don't want it too loud, but wouldn't care if the gutted cats make it sound a little tougher.

 

Get a set of Magnaflows high flow cats.....one for each side......they will still let you pass emissions and improve flow for a lot less than OEM cats.

 

he may not need the eliminators. I had my cats cut off, i've got an x pipe and dual flows and my light came on maybe 4 times in the past year, but it hasnt been on in about 3 months and my truck is fine. i wouldnt reccomend spending the money on eliminators unless you have too...

 

Bad news. I took it to a shop today to look at having them either put in a universal cat, or see about gutting the cat for me (I have no access to a welder to put it back up if I cut it down).

They are convinced it is not the cat. They said it is definitely running on seven cylinders right now, and that best case scenario is a dead fuel injector. Worst case scenario is something got into the cylinder (hopefully not a blown gasket/head/etc, oil was fine last time I changed it).

Any thoughts?

 

try some seafoam, if the injector is not too bad it might clear it up. I doubt its blown head gasket, esp. since you havent complained about overheating.

 

No overheating at all. The temperature gauge is always pretty much dead center.


I suppose trying Seafoam couldn't hurt. But if the injector is completely gone (which the shop said the cylinder is completely dead), I wonder if it has a shot of helping it at this point.

 

Just FYI everwhere i read on here they say the the gauges are pretty much there, they really dont tell you much until its too late. IE- I drove my truck for a day with no fan, and my needle hardly ever moved, but i knew when it started to get hot(the AC started to get warm). Also in the super duty trucks the tranny temp gauge doesnt show in the yellow or red zone until damage has already started.

If the injector is really bad, then i would just buy 8 new ones since they are soo old, or get them rebuilt.

 

My problem is that I don't want to spend $800+ for 8 new injectors. I mean, the truck has 206,000 miles on it. I've put several hundred into it in the last couple of months between brakes, plugs, wires, coil pack, etc. I really don't want to have $2k+ in this truck within a couple of months. Due to a job situation, it's likely I'll be getting a company SUV within the next 12-18 months (that I can use for personal use), so I mainly just want to keep my F150 alive until then. Anything beyond that is bonus.

 

you can get 8 injectors for under $300 from Summit, maybe try the local autoparts stores and see how much 1 injector is and just replace the bad one.

 

The Autozone by me sells them for $95/each. Or, the shop I go to will install the one I need for about $250.

 

Im not sure how mechanically inclined you are, but it isnt all that hard to replace injectors. It would probably take 4-5 hours for someone who doesnt really know what to do. Go get a manual it will make it easier.
I would much rather spend $300 on 8 new injectors than $250 for a shop to replace 1 injector.
How to change injectors:
-Get rid of fuel pressure(unplug inertia switch and try to start)
-Blow out all dirt around injectors
-Remove bolts holding down injector rail
-Remove old injectors(make sure you get all the o-rings out)
-Lube new o-rings on the new injectors
-Push new injectors back into place
-Put injector rail back on and plug in inertia switch
-Start and check for leaks
-If no leaks, take for a drive