Hi,
I’ve got a quick question. I’ve got a 1988 4runner and think my cat might be plugged up, so I was just curious if I could just remove it. I have never removed a cat from an EFI engine; I figure it should be fine, just wanted to know for sure.


Thanks,
Jake

 

Yes you can, but you will find (search and see) that most people dont like their cats gone. I did mine and all it did was stink, horribly. IMO get a carsound (magnaflow) replacment...

but to answer your original question, it wont affect your EFI at all.

 

running a straight pipe is just annoying...i think you get a much better sound and smell out of a magnaflow highflow. if your in the market hit up cootees with a pm. he hooked me up with one in 2 days....

 

Please don't run without a converter. That stuff up there , in the air that causes athsma, etc. (smog) is caused by the crap coming out of YOUR (and my) exhaust. Running without a catalytic converter is like driving 20 cars from the 1970s. We all make polution, why add to it unecessarily. That whole tread lightly bit includes the air.
Sorry for the rant, but there it is.

 

It affected mine. I suspect it caused the 02 sensor to report faulty readings, therefore causing my idle to fluctuate between normal and lower than normal. Sometimes I thought the engine was gonna die. I put a Carsound cat on, and it fixed the idle issue, and I noticed no performance loss from it. I actually gained some low end torque without sacrificing high end HP.

Plus, it's horrible for the environment. Don't hack it off.

 

Well the O2 sensor is actually upstream of the cat so it shouldnt alter the readings of it... Im willing to bet the idle issues were propagated by the lack of backpressure, turning up the idle probably would have helped. But I agree on a NA gasser id leave the cats. Now a turbocharged application would be a whole different ballgame!

 

Right, but it's pretty close and takes a 360* reading, so I'm sure the lack of backpressure (read, exhaust gas) had some effect on it's reading.

 

No, it does not affect the O2 sensor.

 

where can i get a carsound cat at? I am very interested and what kind of price am i looking at?

 

You can buy a comparable replacement cat at any local muffler shop, ie.. Midas, Mieneke, etc. The O2 sensor is not in the loop at idle.

 

I bought a chepo cat at advanced auto for about $99. It was a direct fit and works fine. I could not pass inspection with my old one ewven though it still performed fine.

 

i don't mean to be liberal ( b/c i sure as hell am not) but i'd have to agree that its time to actually start thinking about pollution control. after living in the bay area, ca for the past 19 yrs, the smog has definitely gotten more and more noticable. before now i always thought it was such trash how ca smogs cars, but now i realize it's a good thing...

 

Carsound 14'' $62 shiped Carsound 16'' $67 shiped .... i took off my cat on my 22re and it didint do nothing but make it a little louder plus you can get a ticket for not haveing one

 

I ran my turbo Eclipse cat-free for performance reasons but on a NA engine the gains are so insignificant it's not worth the trouble of adding pollution;my Eclipse also only saw about 5000 miles a year and was primarily a track car.

 

so you shouldnt run without a cat on a turbo?

 

Shouldn't run without a cat on a fuel injected engine period.

 

Technically and legally you have to have a cat.

But with a turbo you cannot reduce backpressure post turbine enough! Lowering backpressure behind that turbine severely lowers EGTs which help save yer engine. If I do turbo my yota ill be pulling the cat or getting a huge arse cat that will provide zero restriction. Until then im keeping my carsound Hi Flow cat!

 

That's true, but information needs to be added. The 5VZ has two sensors; one before the cat, and one after. Chris' idle probably got jacked up because the second "sniffer" saw much lower EGT's, therefore the signal back to the ECU was whacked out (my theory anyway).

I agree with others, it is best to run a cat on a daily-driven vehicle. Carsound is the way to go.