Hello Well I have searched and nothing really will tells me exaclly whats going On.. Here is the problem..

2005 SS 71 000Kms

about 4 months ago i noticed every once and awile my car felt like it had a hard shift.. one day my check engine light came on soo i check it.. 2 codes were Throw 1 was my 2nd 02 sensor witch i guesse is the cat and the 2nd code was like a 18** i donno exaclly but it said on the scanner Long/hard shift..


Never happend offten soo then i started thinking whats going on..

Every Time this happens it doesnt happen Right away the car has to warm up. this only happend probly 2 times a month. but latly its been like once a week... Soo I start the car always drive's and shifts fine but when it dose do the long/hard shift it would not be untill about 20 mins of stright driving then it starts to do the hard shifting... Once i turn car off for about 5-10 mins problem is gone.. I dont do lots long driving Its only work and back and mabby to run for some parts for work soo 10-30mins constand driving..


Im not sure what it can be ( possibly the cat ? it throws that code 3 times now. ) I just want to figure out this problem befor i do my exhust.

 

I thought I remember reading somewhere that if your catalytic converter is clogged, it will make your computer think your transmission is slipping, causing it to increase line pressure which results in harsh shifts. I dont know if that is true or not but it wouldnt hurt to check it out. Maybe someone else can verify or disprove that statement.

 

yeah a clogged cat can make the car feel like that at times. also should feel like you are being robbed acceleration.

 

I had a 01 SS and it was shifting hard after getting warm and then it started feeling slow and sure enough it was the cat..I would have it checked because they told me that if i wouldnt have noticed it when i did it could of blown out my head casket with the back pressure..im no mechanic but i would look into that..i had my local chevy dealer do mine because i was in a pinch and it was big bucks...

 

Alright this all seems to add up right. becase the Rear 02 sensor code did come up first and it wasnt till about a month later that i notised the hard shift...

blacksheep"also should feel like you are being robbed acceleration" Thats Exaclly what i was thinking too but it really dose not seem im looseing acceleration Unless this car has ALOT more power then I THINK.. Thats also why I was thinking the cat is fine because the car seems like it has alot of power... Now what am i going to do.... HMM

 

Could have had a clogged cat for a long time.

Since it's an 05 it's going to be weird to get a ZZP Downpipe, but that's a great way to replace your restrictive downpipe and your old cat for a high-flow.

 

Well Sicne all Leads lead to the Cat Im not Going stock im Going with a zzp dp for sure. I was also thinking No cat??? because Well its 05 even with high-flow cat the stupied thing is going to throw codes.. Well Its x-mass SomeOne wanna buy me DP?

Would it be better to have the high-flow or no cat?

No Huge Plans for this car. CAI/ Program PCM/ Would Like smaller pully
73Nova is where Most the $$Flows

 

Depends on where you live and the local laws regarding catalytic converters.

 

But im stumped on this Because if my cat was clogged, I would lose Power? Like really i took it out today and got it nice and warm. and its -1 here soo the supercharger love's it.. and really She FLYs. its Quick i cant see it being clogged.
But i guesse if its throwing p420 codes it must be starting. Would love to get zzp DP and feel the power.. but its DECEMBER SNOW WILL BE HERE ANYDAY. and -40 weather


As local laws regarding catalytic converters I think it doesn't matter your supose to have one for safty but here in Manitoba they never do checks. only when you safty the car and you only need safty if your selling or registering..

 

It couldn't hurt to get a new downpipe and cat, or go catless. First of all, check your transmission fluid level. If your problems still persist, then you have a definate transmission problem.