AI95GSR

So I've done some reading about the catalytic converter on my 95 Gsr and turns out it adds certain amount of back pressure... So some people say you can remove it some say you cant....Here's my situation yesterday I removed my old catback exhaust and installed a new one.. The old one was kinda pieced together by the old owner and I just thought it looked bad so I got a nice new one... While at the garage doing the installation my mechanic said that I could remove my cat to get better sound and flow since I have a header as well. So he removed the catalyic converter and just put a piece of straight pipe in instead. Before the installation my car ran perfect. Now when I get to about 5000rpm it starts to studder and then when I hit the IAB around 5800 it stops.... Does this sound like a issue stemming from removing the cat. And if so will a high flow car make enough back pressure I've never had one I'm not sure of they are completely hallow or not... if not I still have the stock cat.. Please help me out... I hate to see my baby running like this...Thanks...Steve.

HondaPartsHero

Removing the cat won't cause the studder. What other things were done? Check engine on?

AI95GSR

No check engine light at all... no codes

AI95GSR

My car is obd1 02 before the cat... Do you think since the air is flowing quicker now I need to reset my ecu being it has my old flow settings stored?..

B20VtecVillain

Good advice to reset ECU, but as was stated I don't see how the cat could cause a stutter. Changes to the exhaust will change the air/fuel ratio of your engine though since, as you said, airflow is increased, so resetting the ECU is a good idea. As far as the cat goes, it's good for the environment and thas about it. The back pressure it creates actually chokes the exhaust a bit and therefore an increase of power is usually had by removing a stock cat and using a straight pipe
(AKA-test pipe) or high flow aftermarket cat. This is especially true when removing an older cat from a vehicle because over time they become clogged and choke your engine even more. Those people who say you need that extra backpressure are usually idiots with no understanding of the concept of what a good exhaust system really is. Your engine will be fine without the convertir, just watch out during inspection time if you live in a state that has visual/sniffer tests.

AI95GSR

Well in a way that stinks that it's not needed, because I was hoping that was the fix.. It's very odd indeed. It ran top notch on the way to the garage and after removing the cat and swapping the catback out for my new one I now am dealing with this issue I speak of. I made another post about this because I had more information and wasn't sure how to edit this one as I'm new to this site and use a older phone... So If I ease the rpms up to 5 or 6k you don't notice it all basically but as soon as you floor it that's it bucks some and jumps and when the IAB hits around 5800 it smooths out some but still does it.. Also it does it in every gear first and second being the worst third being bad aswell but a little better. 4th is getting better and 5th you don't basically feel it much at all but can hear it and feel it but very slightly... i did reset ecu it didn't help. Again no check engine.. Plugs are less than 500 miles on them... i don't know where to start... down under 5000 Rpms it runs and picks up speed smooth and pretty quick... and ideas please...thanks

wunfstgsr

Sounds like a problem with your vtec engagment you can always Invest in a hondata ems and have it tuned it might run better.

AI95GSR

Well I do want to buy a hondata and due a tune but untill I have a grand for s300 and a tune. ..how do you reset vtec never heard of doing that. ..

wunfstgsr

What i meant by Reset vtec was by having a tuner adjust the engagement point, i would just get a s100 and get it tuned you don't at all need a s300! you can even get free software to be chipped and get it tuned.

AI95GSR

Well my local shops use s300 only which stinks but anyhow untill I get a tune there has to be a explanation to how one day it's fine then not... any things I can check for I'm good with following directions and doing minor to medium things to cars

Creator

iTrader: (1)

A lot of shops will only do s300 now. Personally it sounds like a spark issue. Maybe the distibutor was already on it's way out, and can't keep up with the extra flow now. Take your cap off and inspect it and the distributor rotor. There are ways to test the coil and the ignition control module that are within the distributor. I don't have a multimeter and have never done so. Maybe someone else can expand on this?

AI95GSR

Thanks for info I have been searching how to inspect my distributor so if anyone had more input on what to look for let me know thanks..

rikkireyes

was that test pipe plumbed for both o2 sensors?

AI95GSR

I only have one 02 sensor and it's actually before the cat

wunfstgsr

It could be a spark issue, Look for a loose rotor in the distributor, also inspect the tip of the rotor it may be worn out. Check your spark plugs as well.

silvertaxasteg

Not immediately productive to your problem at hand, but interesting reading, none the less.

Advanced Exhaust Tech II : Backpressure and Area - Team Integra Forums - Team Integra

tamboo

Advanced Ignition Troubleshooting - Team Integra Forums - Team Integra

AI95GSR

Thanks I'll start reating both now

AI95GSR

When I click the thread it just takes me to the main page about the advanced timing how do I get to the thread so I can read it

AI95GSR

Ok so something new to add... today the car still sputters in vtec and I got code 22 vtec oil pressure I believe it was so we changed the oil cleaned the solenoid the screen was clean. Put it back together and it still sputters but when vtec is un plugged the car runs through the upper rpms just fine. Also there is no dent in my oil pan... can anyone give me some ideas of what to try thanks...

wunfstgsr

Did you ever reset the ecu? Pull the ecu fuse or unplug the ecu for 5 mins and plug it back.

AI95GSR

I did reset the ecu after installing the new exhaust and removing the cat but not after getting that code and changing the oil... i will try that tomorrow though could reseting the ecu after oil change play a roll??

wunfstgsr

Yes it can remove the cell code and give you back your vtec, also pull off the upper part of the vtec solinoid the screen there may be clogged and be your issue. There's two parts to the b series vtec solinoid.

AI95GSR

Ok will do I never actually lost my vtec untill that code came on then vtec no longer worked but before that it had and still had a bad stutter in vtec starting at about 5300 rpms. When I got the cel code I turned the car off and turned it back on the light was gone but still stuttered in vtec like before also when I removed the vtec solenoid are you speaking of the screen that is on the face of the solenoid that kinda rectangular shaped in the middle of the gasket and it also comes out with the gasket of that Is the one your speaking of then it was spotless and I cleaned it anyway but yet again the stutter is still there. And like I said earlier the car ran fine untill I removed the stock cat converter and replaced it with a straight pipe that my mechanic welded up for me. I really feel that the cat is playing a role for some reason but at this point who knows... thanks I'll reset ecu first thing in morning for the hell of it...

EnjoyTheRideDC2

iTrader: (1)

Sounds like you might be low on oil....That "stutter" you're experiencing sounds vtec related and not due to your exhaust setup. Park your car somewhere flat and check oil levels with the engine cold. For all we know, you might think 4qts of oil is all you needed when you did your oil change.



Regarding the VTEC solenoid, notice the 3 bolts on the top of the solenoid? When you remove them, there's another seal under there. Chances are, you're going to need to replace your solenoid gasket if you've unbolted the solenoid from the cylinder head to clean it. Otherwise, expect to have a new small oil leak coming from that area.

You need to clear your CEL, make sure you have your oil filled to the correct level, warm up your engine, and then go for a test drive. Dont be a genius and start trying to hit vtec a couple of minutes after you just started up your cold engine.