Question about 2001 Isuzu Trooper

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2000 Isuzu Trooper

I have bad Cat converters and O2 sensors on my 2000 Trooper. The cost to replace them is about $1600 dollars, only slightly less than what the vehicle is probably worth. Will I have problems with fuel mileage or performance if I cut them out and straight pipe the exhaust?

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  • Chris Hutchinson
    Chris Hutchinson Apr 15, 2014

    ??? Anyone out there???

  • John rudov
    John rudov Apr 15, 2014

    You can remove converter but it will not pass emissions

  • Chris Hutchinson
    Chris Hutchinson Apr 15, 2014

    What about the 02 sensors? I know the engine light will stay on and that the vehicle won't pass emissions, I am just wondering if it will affect gas mileage good/bad and or performance?



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  • Isuzu Master
  • 20,706 Answers

The first question, is why did you replace them.

  • they looked bad. ?

  • they failed smog?

  • a guess. ?

  • Poor engine power, or other issues driving? not stated?

you spent 1600 just to throw them a way, (i bet the old ones were good and exhaust leaks , true cause, it is most the time)

gee, they do no harm, why remove them? and its very illegal to do in USA>and removal proves tampering. why do that.>????

and you paid too much, aftermarket cats are cheap and any muffler shop can weld them in (post assumes, not in P.R. of California)

At home new cats are like $99 each and my tig/mig welder, bam

in a shop, add what $200 labor, (4 hours) and bam,

1600 is rip.

well lots of questions, i can answer most, if you just answer

which of the 3 engine you have in that car. (or up to 9 , all countries)

displacment exaclty ,

in 2000 it was 3 engines.2.2 ,3.2, 3.5l, state side.

The car is OBD2 here, (where are you? illl assume USA.

In the USA, the car will fail P0420s and rear cat O2s sensors will fail.

all cars from 1996 to now do that in USA.

and the DASH CEL will glow. running and all cars fail for just that alone.


On some engine,s (older) the EGR fails if the CATS is missing.

this engine has a pure electric EGR, (no vacuum)

and will work cats missing.

this engine runs a MAF sensor and will adjust for any changes

in the exhaust, you do. it measures true air flow, unlike other cars

with only MAP operations. Your EFI runs Air Density system.

The best.

CAT present, then gone.

MPG, it will not help MPG, just cruising, how could it.?

the throttle is like 1/2 way used, cruising. so there will be no change.

Point 2, the EFI is TUNED for stock, and NOT for missing parts.

sorry, that is a fact.

Performance, sure you can get better performance

but you will need to say where?> at what RPM and speed.

all exhausts on all race cars are tuned for the usage factor.

did you know most racing setups suck on the road at low speeds?

like huge exhausts, and other things!

the exhaust will make best power with high velocity system on the street, why not just run a stock car.?

after all , the car is worth more money stock (resales)(

and would you buy a hacked up car, or pay top dollar for one?

Performance is an infinity topic and has no limits.

how FA$T do you WI$H to go? $$$$$$$$$$$

Posted on Jun 01, 2014


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SOURCE: O2 Sensor Problems-1996 Isuzu Trooper

they are very easy to replace .
all you need to do is go to autozone and get the right parts.
then you will find the old parts on the exhaust system.
unplug the first one you find and unscrew it from the exhaust and refit the proper replacment part.plug wire back in.thats all you will need to do on the second one also.after that your done.ask auto zone after that to reset your codes for free with the code checker.then get a can of carb cleaner and spray out the throttle body of all the black carbon around the throttle plate.use a clean rag only.make sure its clean around the plate.
thewn fill your gas tank with supperunlead dont get the crappy gas any more cause it causes the carbon to build you will get better gas your ready for an inspection sticker.
hope this helps
keep me posted

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SOURCE: 2000 isuzu trooper: OBD-II Trouble Code: P0401 Insufficient EGR F

Your SUV is really giving you a hard time, lol. Sorry but I've had those days too.
I would try to check if you have blocked EGR passages. If ok check for restricted MAP sensor vacuum hose/passage or restricted exhaust. I know you replaced the CAT but if the muffler is blocked then there would still be a restriction. Also check the wiring and connection to the MAP sensor.

Posted on Apr 28, 2010

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