1997 xlt extra cab 5spd 2wd 4.0 sluggish

[Rick W]

loud and kind of comical

Like me?

 

[sgtsandman]

Like me?

Loud, yes. Comical... well...

 

[Rick W]

Man, I just don’t understand something. All you guys are supposed to be the be-all end-all experts on this stuff. I don’t understand why nobody can give me a specific answer and action plan on a truck they’ve never seen, that’s 1000 miles away from you, that has 320,000 miles on it, that has also been highly modified. And I thought you guys were experts.



Seriously, though, I greatly appreciate all the comments and advice. I was considering pulling the top off the engine to change the injectors, and some other things, but I know just enough to know that that doesn’t feel right to me. I’m coming to the conclusion that it is the catalytic converter, and that’s a very easy thing to check and start with.

My rationale: when I noticed the drop in power, and then a significant drop in power, I noticed a ton of soot in the driver side exhaust stack, and I changed the plugs. One was loose in the threads, but very loose w/blow by from not being seated properly, and it was black with soot. That large amount of soot had me thinking the cat might be partially plugged.

Then I added the varnish remover/injector cleaner, and the situation immediately got much worse. Part of my thinking was I pushed crud into the injectors, but my current thinking is any crud that came loose further impacted the cat.

Side thought: A few of you have seen the truck, and when my exhaust guy put in the dual exhaust and stacks, he kind of did a half assed job of looping the driver side underneath the frame right behind the cat, which gives me another reason to mess with that area.

So here’s the action plan: I didn’t know you could buy a cat for like $80. The cats I’ve bought before were in the $500 and up range. I ordered a couple band clamps, and a short piece of 2 inch pipe to evaluate the problem. I’m going to cut the cat out and put the straight pipe in and see if that solves the problem. If it does solve the problem, I’ll buy the replacement cat and go to a better shop to put it in and do a better job running the pipe under the frame. What I went to dual exhaust and the stacks, the gas tank was in the way on the driver side, hence routing the pipe under the frame. I’m not worried about clearance, this truck will never see any significant off the pavement use.

If that doesn’t work, I’m going buy all the parts I can think of, and let my shade tree take the upper intake off, and maybe check some other things like the rockers and push rods.

The parts are supposed to be here in about a week.

 

[sgtsandman]

Part of the reason for the disparity in the cost of catalytic converters is what they are built to meet. California emissions models are going to be more expensive than the ones that meet federal standards.

Then add if they are OEM or aftermarket.

The OEM ones for my 2011 are 3x the price of the aftermarket one I put in my truck. The CEL stays out and it passes the OBD II check for emissions testing over several years now. So, good enough for me.

 

[Rick W]

Part of the reason for the disparity in the cost of catalytic converters is what they are built to meet. California emissions models are going to be more expensive than the ones that meet federal standards.

Then add if they are OEM or aftermarket.

The OEM ones for my 2011 are 3x the price of the aftermarket one I put in my truck. The CEL stays out and it passes the OBD II check for emissions testing over several years now. So, good enough for me.

Understood. When I bought the 97 Ranger, one of the door handles was really loose. I dreaded it until I found out you could buy one for like $15 or $20.

I had a Mercedes that I bought new, a 300SDL, where the door handle failed after 200,000 miles. The part was around $500. I ran it to 327,000 miles, and I’d still be driving it, except it got totaled.

I had a couple similar high-end cars that I had to replace the cats on, ouch, which is why I feared looking at the catalytic converter on this thing.

 

[sgtsandman]

Understood. When I bought the 97 Ranger, one of the door handles was really loose. I dreaded it until I found out you could buy one for like $15 or $20.

I had a Mercedes that I bought new, a 300SDL, where the door handle failed after 200,000 miles. The part was around $500. I ran it to 327,000 miles, and I’d still be driving it, except it got totaled.

I had a couple similar high-end cars that I had to replace the cats on, ouch, which is why I feared looking at the catalytic converter on this thing.

One for mine was about $200. Still an ouch but better than the $600 for the OEM one. @lil_Blue_Ford and I did have to do a repair on it either last year or the year before because the weld on the flange that attaches it to the pipe on the other cat had rusted out. So far, it's holding up fine. I did spray the repair with some high temp grill spray paint after the repair. So, that might have helped.

It has been on the truck for a few years now. So, it has been holding up pretty well all considering.

 

[lil_Blue_Ford]

My F-150 got a weld-on OEM cat many years ago, it was cheaper than the whole pipe assembly by a lot, but I don’t know that those are an option anymore.

My Choptop and green Ranger both have universal stainless high-flow aftermarket cats welded on. Way cheaper than OEM. Both were done by a local exhaust shop when I had them make me stainless exhaust all the way back. At some point I intend to have my own exhaust bender because Jr is running the local shop now and he’s not what his dad is…

 

[Shran]

Don't go hacking the exhaust apart and replacing stuff without knowing that you need to first. It may not even be a plugged up cat. Just trying to save you some unnecessary work.

 

[Uncle Gump]

Test it with a vacuum gauge...

 

[Rick W]

Don't go hacking the exhaust apart and replacing stuff without knowing that you need to first. It may not even be a plugged up cat. Just trying to save you some unnecessary work.

After a couple months of thinking about it, I think it’s the lesser of evils, and like I said above, I have to fix the part that swings under the frame anyway. So I’m going to chop it and put in a test piece, and if that’s the problem, I’m going to have the crooked section fixed when I put the new cat in. I’ve been wanting to do that for a long time, so it won’t be wasted money. But thanks, as always.

 

[RobWigglezz]

I've been soaking the flange bolts on the Y pipe with the cats for a month now. Just delaying the inevitability of having to cut the bolts after snapping the first one I try. I miss my 2.5l that didn't involve removing exhaust to pull the trans

 

[Jim Oaks]

@Rick W I've been thinking for some time that my 1996 4.0 doesn't have the power it had back when I got it in 2004 and have wondered if the cat isn't flowing. It will be interesting to see how yours runs with a new cat.

 

[lil_Blue_Ford]

So, I’m just gonna throw this out there for giggles…

When I replaced the gas tank in my Choptop with the 4.0, I was going to re-use the pump that was in the old tank because it still pumped fuel. When I got the old tank out, the lock ring and pump were really crispy looking so I changed my mind and opted for a new pump. Never thought to check fuel pressure. Truck runs and drives noticeably better with the new pump and it felt even happier after I replaced the fuel lines that had pinholes. I never gave it a thought until apparently the new pump had the pressure to make the old lines leak a little more. Joys of owning older vehicles I guess. Just some food for thought…

 

[Rick W]

@Rick W I've been thinking for some time that my 1996 4.0 doesn't have the power it had back when I got it in 2004 and have wondered if the cat isn't flowing. It will be interesting to see how yours runs with a new cat.

My parts won’t be here for about a week, and I’ve been chomping at the bit to see if the cat is the problem. @Shran suggested pulling the O2 sensor, but when I looked at that, the way the guy did my dual exhaust, I’m afraid of messing it up. No room to swing a wrench.

I ordered four band clamps, and then a 4’ piece of flexible exhaust pipe. I hate the flexible stuff for long-term, but I’m hoping to be able to put it together and get the bends correct, then I can get a proper replacement when I put the cat back in.

Then I had the idea that I could saw cut 3/4 of the way through the front side of the pipe feeding the cat and take a loud test drive to see if that solves the problem. If so, I could move straight to the cat instead of a temporary straight pipe. The thing is pretty loud anyway with the tiny glass packs and the stacks. If I try it and it works, I can also be a teenager and cover it up with a soup can and hose clamps until my band clamps come in. I can’t drive it the way it is now.

I’ll keep you posted.

I’ll throw out something else to give everybody a headache. There’s a pretty complex set of curves from the back of the cat, looping under the frame, and then going up a little bit to feed the glass pack that feeds the stack that’s literally at the back of the cab. I’ve had the thought for a while that if a pipe can’t be bent without looking like an eye sore, I may just make a flat steel box, kind of like a cigar box, that can mount horizontally under the frame, and feed it from the top on the inside side, and having a exit on the top outside side that goes into the muffler. It would hug the frame and be parallel. When I got the truck, it was two 2” pipes into one 2 1/2 inch exhaust system out the back. I doubt it was the original system.

When I split it to dual exhaust, I have 2 inch pipes feeding 2 1/2 inch pipes, which feeds the 3 inch stacks, the cross-sectional area increases at every step, so I wasn’t worried about any back pressure from the system. The box would be fabricated so it has a larger cross-sectional area than the pipe on either end of it.

I’m still planning on some kind of Nerf bars or running boards, so the whole thing probably won’t be seen anyway, but I would know it’s there. All a big toy for me! When I get it all figured out, I can get somebody to weld it back and get rid of all the clamps and such.