No catalytic converter affect 2.5L?!

[Jethro_54]

Having issues with this 99 Ranger 2.5L running really rough. Previous owner torched a hole in the cat thinking it was plugged. I know with older trucks they will run fine without a cat but I also know some newer vehicles need the cat to run properly. If I cut the catalytic converter out and replace it with a pipe (temporarily) will it run okay? Just need to do something with the exhaust until I can diagnose what is wrong with the truck. I don't want to spend the money on the cat if I end up having to junk or part out the truck. No obd2 codes currently which I find very strange.

 

[Explorin94]

Having issues with this 99 Ranger 2.5L running really rough. Previous owner torched a hole in the cat thinking it was plugged. I know with older trucks they will run fine without a cat but I also know some newer vehicles need the cat to run properly. If I cut the catalytic converter out and replace it with a pipe (temporarily) will it run okay? Just need to do something with the exhaust until I can diagnose what is wrong with the truck. I don't want to spend the money on the cat if I end up having to junk or part out the truck. No obd2 codes currently which I find very strange.

For testing purposes running without a convertor is fine. If the previous owner cut a hole in it and thought it was plugged then unfortunately you have to pay the price to replace that convertor. What he should have done was pulled the o2 sensor to test it. Sometimes with plugged cats you will experience no power and will have extreme back pressure before the cat. Do a compression check on the cylinders also and where is the truck at for tune up?

 

[Jethro_54]

Yeah I just bought the truck last night. I already plan on buying one from Rock Auto once I get it running correctly. Just don't want to spend $158 on one if I don't figure out what is wrong with the truck. I agree with pulling the o2 unfortunately it's too late for that. I would have done a compression test before I bought it but a friend of mine has my compression tester and he was sleeping when I went to get the truck...bad part about lending tools out!

The truck has new coil packs, IAC valve, air filter, some new plug wires?! The MAF sensor is a reman...which I cleaned and I unplugged it while it was running and it shut off instantly. Tested new IAC valve, TPS, fuel pressure, and spark at each plug. I will do a compression test as soon as I get my compression tester back. I don't have a clue about it's history as far as tune ups or if the timing has been done. Truck has 158k miles.

 

[RonD]

No engine "needs" Cat to run, this often comes from the "back pressure myth", OBD II will throw a code if Cat is not cleaning exhaust, but engine would still run fine

All vehicles that came with Cat converters need Cat converters or there is a $2,500 Federal fine, it also effects my children so get one back on ASAP

Vacuum gauge is a cheap and very good diagnostic tool.
Tells you if there is blocked exhaust, valve condition, ring condition, leaks........
And it cleans up afterwards........well maybe that's a stretch, lol
No tool box should be without one

 

[Jethro_54]

Okay haha and yes once I get it running right that's the first thing I'm ordering! I do also have a vacuum gauge...just haven't learned how to do all the different testing with it quite yet! In the morning I plan on doing a few things to it then I'll post an update. Thanks for all the help!!!

 

[RonD]

Good read here on vacuum gauge tests and results:
http://www.gregsengine.com/using-a-vacuum-gauge.html

 

[racsan]

i actually have a vac guage installed full time on my truck, gives me a general idea of how much load the engine is under.

 

[Andy D]

How big a hole? Wabbout just patching what you have?

 

[Captain Ledd]

Summit Racing has 3-way universal catalytic converters starting around $40-$45

They're actually quite affordable.

 

[Road Angels]

check the egr valve and system, pull the vacuum line and plug it, see if it smooths out at Idle , also the pintle valve may be stuck open from carbon in the egr valve its self

 

[Jethro_54]

Soooo I just stuck a chunk of pipe in the place of the cat temporarily...much quieter. I can hear myself think now lol. Ran a compression test. Cylinders 3 and 4 are around 25 psi...1 and 2 are good. Thinking either carbon buildup on the valves or head gasket. I just sucked about 3/4 of a can of seafoam through the brake booster vacuum line to hopefully break up any carbon. Letting it sit for about a half hour then I'll go beat the piss out of it. I'll post an update when I'm done!

 

[racsan]

with the middle 2 extremly low, im thinking head gasket/maybe cracked head. cant hurt it with seafoam though....

 

[Jethro_54]

I ended up putting a little oil down cylinder 4 and ran another compression test...jumped right up to about 130. I ended up picking up a motor for $300 from a local junkyard. Threw it in the other night and she runs like a top. Got the cat on order from rockauto. Thanks for the help guys!