If theoretically I was to remove my cat would this cause the check engine light to always be on?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
No cat with TBI check engine light???
- Thread starter MTBLAZER89
- Start date
sled_dog
1 ton status
o2 sensor is before the cat can't really see it causing a problem. I ran my 95 pickup with nothing more than Y pipe and a flowmaster 40 series with dual outlets. Never tripped the Check Engine Light. Heck running right out of the y pipe didn't /forums/images/graemlins/wink.gif.
as long as you have OBD 1 you should have no problem
if you have OBD 2 you need a o2 sensor sim from jegs or summit
if you have OBD 2 you need a o2 sensor sim from jegs or summit
I did this to a 98 truck & it did kick the light on.
Without the backpresure it was confusing the computer.
I ended up putting a hi-flo aftermarket cat on it.
I know the tbi & vortec's are different but I think it will cause you problems.
Without the backpresure it was confusing the computer.
I ended up putting a hi-flo aftermarket cat on it.
I know the tbi & vortec's are different but I think it will cause you problems.
sled_dog
1 ton status
your problem was simple, the 96+ chevys have at least 3 o2 sensors. 1 on each pipe of the y pipe, and one right AFTER the cat. This means if the cat is not there of course the system will know. It had nothing to do with backpressure.
that is why you get a sim it plugs in where the o2 sensor was and tells the computer every thing is fine so you do not get any codes
justinf
1/2 ton status
Nope, like Sled-dog I ran my old 90 stepside with headers, Y-pipe, straight into a flowmaster, no cat, and never had a problem. /forums/images/graemlins/waytogo.gif
K5MONSTERCHEV
1/2 ton status
[ QUOTE ]
I did this to a 98 truck & it did kick the light on.
Without the backpresure it was confusing the computer.
I ended up putting a hi-flo aftermarket cat on it.
I know the tbi & vortec's are different but I think it will cause you problems.
[/ QUOTE ]
Thats because OBDII has Pre and Post O2 sensors. On your '98 it has 4, and it would throw a code because both post O2 sensors will be switching, and there not supposed to be, not because of backpressure.
No it shouldnt set a code on you TBI.
I did this to a 98 truck & it did kick the light on.
Without the backpresure it was confusing the computer.
I ended up putting a hi-flo aftermarket cat on it.
I know the tbi & vortec's are different but I think it will cause you problems.
[/ QUOTE ]
Thats because OBDII has Pre and Post O2 sensors. On your '98 it has 4, and it would throw a code because both post O2 sensors will be switching, and there not supposed to be, not because of backpressure.
No it shouldnt set a code on you TBI.
Derf00
1/2 ton status
Gotta agree here. My '90 w/MPFI has headers, y-pipe into a Flowmaster. No problems.
I have been running one of my TBI rides with no cat for over 10 yrs and have never set a code yet. These systems are archaic in today's technology (which is why I like them soooo much /forums/images/graemlins/thumb.gif).
Bryan,
No it wont. On our trucks the o2 sensor is in the driver side manifold. So it will not cause any problems by removing the cat. And all the shopd here wont take your cat off but if you dont have one they wont make you put one on either. So take it off.
No it wont. On our trucks the o2 sensor is in the driver side manifold. So it will not cause any problems by removing the cat. And all the shopd here wont take your cat off but if you dont have one they wont make you put one on either. So take it off.
jwduke
1/2 ton status
Brian, I removed the cat from my '87 & I have had no problems.
84_Chevy_K10
Banned
My 87 doesn't have a cat either.
Hmm where the hell did it go? /forums/images/graemlins/rotfl.gif
Hmm where the hell did it go? /forums/images/graemlins/rotfl.gif
i just swapped my high flow cat out for a straight pipe when i installed headers. i had the muffler shop fab it up to be removable with 3 bolt flanges. so i can replace the cat when it comes time to smog it.
i have found two problems with this. first, i can smell excessive exhaust odors, like unburned fuel that the cat would have cleaned up. now i cant have my back window down, or even the front window at lights without getting a nasty smell.
second problem is now when i drive on the freeway, and just cruise with very light throttle, the light comes on. i think its a code 32. what do you guys think? i think i'll replace the cat and see if it goes away. i dont like the smell anyway.
i have found two problems with this. first, i can smell excessive exhaust odors, like unburned fuel that the cat would have cleaned up. now i cant have my back window down, or even the front window at lights without getting a nasty smell.
second problem is now when i drive on the freeway, and just cruise with very light throttle, the light comes on. i think its a code 32. what do you guys think? i think i'll replace the cat and see if it goes away. i dont like the smell anyway.
sled_dog
1 ton status
at this point I don't see a reason to not throw in a high flow cat. I'm going to on my Suburban, not my K5 just for ease but my next trail rig may very well get one.
raelayotte
Registered Member
i have had my cat off for 5 years know and no check light yet /forums/images/graemlins/k5.gif <font color="yellow"> </font>
