S&S header install and weird transmission shifting

[chris_gt_74]

Yes my car still has a cat. I do not know what brand but it is a high flow cat. No it's not clogged either. I checked it before installing the headers 3 weeks ago since the headers and downpipe are used.

[gectek]

The only reason the CEL blinks is to show a MAJOR misfire. If the misfires are slight, they will only allow the light to come on. Either way, it does not make the car go into open loop.

[gectek]

High flow cats will not condition the signal enough for older vehicles to like it. You must have that code turned off. If you do not, alot of other routines will not run.

[chris_gt_74]

Currently when it shows up I just erase the code with my scanner until the next time which til this last time was like 2 weeks ago with plenty of driving everyday in between. I do plan on getting it turned off just not yet. When it throws the code there is no noticeable performance change I have felt. I keep it cleared in case it hides a worse code that I wouldn't know about. Plus it's annoying to look at.

[gectek]

You are not too far from me. If you want a quick tune I can arrange that. I am in Longview tx now. I use HP Tuners. I can turn off the code and tune your rig!

[chris_gt_74]

I might take you up on that!. I do however have some things I want to iron out with the car prior to getting it tuned. I still need to get a 2.5" cat back exhaust, swap out my LIM with my replacement from Ben and I'd like to find some low mile 10mm rocker arms w/push rods possibly even the lifters too. I have some valve train noise after my head install that concerns me. I think it is due to having to resort to using fairly worn 10mm rockers in place of my original 8mm one's because I received the wrong year model of heads when I ordered them. I used the old rockers but nothing else. The push rods and lifters were from my car with 95k on them. The 10mm rockers probably have 150k + maybe less. Not sure if that would be the source of my noise or not but it bothers me having the parts mixed like they are. It's my DD so I had no real choice really since it was a last minute find.

[3400-95-Modified]

I thought the SS headers replaced the section of pipe that had the cat on a GA... But maybe I'm wrong.

[chris_gt_74]

Maybe they did originally but I am positive mine has one. I bought it off of Ben since he had a spare set.

[3400-95-Modified]

Call me crazy but looking at this photo of a cat downpipe for a 01 GA if you installed the SS headers with the supplied down pipe you would have to eliminate or move that cat further downstream...



This is the SS set with downpipe.

[chris_gt_74]

Yeah I see what your saying but mine has a cat welded in after that flex section. Ill look for the pic Ben sent me and post it.

[chris_gt_74]

[3400-95-Modified]

ah ok, but looking at that cat there should me MORE than enough of a setup there to clean the exhaust... How old is your second O2 sensor? That actually could be faulty.

Hell I installed this



on my legacy and that was enough to keep the system happy... Until I richened up the mixture at WOT and run it a bit hard then it will throw the 420 code, but under normal driving conditions it was fine with it.

[chris_gt_74]

Well I don't know if it is the original o2 sensor or not so I'm gonna just say 95k. I can say for sure though that prior to putting the headers on I never had the p0420 code in the 3 years I've had the car. I don't get the code very often. Do you know how frequently the pcm runs the efficiency check on the cat? I'm sure there is some interval that would be fairly constant.

[gectek]

Its a complete drive cycle, which can take a few hours or a few days because certain conditions have to be met.

[chris_gt_74]

I drive to and from work 5-6 days a week which is maybe 20 miles round trip each day and then 2-3 days of 40 mile round trip trips to the next town. Based on that I went 2 weeks with no ses light until 2 days after the 56mm to 65mm throttle body swap was done.