Only one header is leaking on the pass. side and the one on the driver side is all sealed up. Will the uneven back pressure result in a rough idle. so far ive replaced damn near the whole ignition system exept the distributor. It still feals like its missin but Im thinkin it could be cause of this leak and it just feals like a miss. It only really feals like its missin at idle the rest of the time it feals good. any ideas?

 

It sure Could.

 

Maybe in closed loop, not in open loop though, IMO. I'd lean more towards ignition system (all the way to the plugs) or a faulty injector.

 

i have an exhaust leak on my drivers side from when i put in my y pipe... i broke a manifold bolt and have never fixed it cause i am just gonna get headers anyway... but at idle it can be very rough sometimes... i think my problem is that my 02s are sensing the extra air and dumping fuel in that is more than needed... bogging and causing a rough idle... but that is just my .02

 

It has nothing to do with the O2.

IT has to do with reduced backpressure from a signifigant exhuast leak.

My car will idle roughly when the back 2 header bolts back out on the pass side.. and its Carbed. No 02's.

 

i know my 02s are reading the false air and dumpin fuel cause you can watch my 02s and see it go lean and then rich all of a sudden!!!

 

A false O2 reading is also a possibility but it would have to be the result of a Huge exhuast leak, considering the position of the O2 sensor.

A lean reading caused by outside Air would not Fluctuate, Because the O2 sesor measures just that, Oxygen. Since the introduction of outside oxygen is present and unchanged, the amount of Fuel the computer Adds Via Block learn to attemp to correct for the Lean O2 reading would have no effect on the Oxygen in the exhuast stream, and the reading would remain lean. The amount of oxygen present has not changed.

I imagine your O2 goes from rich to lean because That is What it is supposed to do, and completely normal operation.

 

Ive had leaks at the manifold and that never resulted in false o2 readings but just recently both ypipe bolts backed out from the header and my o2 read 0-.1 volts all the time.

 

Yea, I dont beleave my problem has anything to do with the o2 sensor cause the driver side is really sealed up and thats the only o2 sensor the big leak is on the pass. side. There is also a dent on the driver side part of the y-pipe so that could result in even higher back pressure on the driver side and with the leak it would be really low on the passenger side. Its got to be this, I have replaced every aspect of the ignition system exept the distributor itself so thats all good. the only other possibility is that I have a bad injector, But I have good power and it runs smooth almost anywere but Idle. So just to make sure you guys ARE saying its possibly the problem right??

 

I am Saying it is definately the problem.

I have Fixed Exhaust leaks at the Y Pipe on a Number of cars, and every one smooth out the idle signifigantly.

 

THANK YOU VERY MUCH BORT62, GLAD I DIDNT GO OUT AND BUY A NEW SET OF INJECTORS. jUST ONE MORE QUIK QUESTION FOR YA. hAVE YOU EVER USED THOSE METAL HEADER GASKETS? tHE REUSABLE ONES? ARE THEY ANY GOOD? OR SHOULD i JUST GO WITH A REGULAR SET OF FEL-PRO's?

 

Ive always just used Standard Felpro SBC exhaust manifold gaskets, Libeally coated with Copper RTV on both sides.

Never had a leakage problem here.

 

YEA i DIDNT FOR A WHILE, BUT THEN MY BOLTS STARTED BACKIN OUT, AND IM AFRAID IF i USE LOCK TITE ILL NEVER GET EM BACK OFF AGAIN. ANY IDEAS??

 

Fact of life with headers -

You need to Tighten the bolts from time to time.

 

I have the same problem, both sides. I'm just too lazy to replace them right now. I hate it how the rear two, (#8cyl) always backs out first. I think when new motor is in and going safety wire. Or just keep a wrench in the car. Headers are cool, but they suck too

 

HOW HARD WOULD IT BE TO GET OUT THE BOLTS LATER IF I USE LOCKTITE NOW ON EM?? WILL I BE ABLE TO GET EM OUT?? I THINK JUST A LITTLE LOCKTITE ON THE TIP OF THEM WOULD SURE YOU A LONG WAY. IF YOU USE A LITTLE IT WOULD STILL KEEP IT IN PLACE BUT WOULDNT BE TOO HARD TO BREAK THE SEAL RIGHT?? I WOULD USE THOSE STAGE 8 LOCKING BOLTS BUT IVE HEARD THERE A REAL PAIN AND THERE NOT EXACTALLY CHEAP. IM JUST SO SICK OF HEARIN THAT DAMN CLICKING NOISE, THE ROUGH IDLE AND THE FACT THAT WHEN IM GOIN UP A HILL IN A LOW GEAR IT SOUNDS LIKE MORE EXAUST IS LEAKING THEN GOIN THROUGH THE EXAUST SYSTEM.

 

Go ahead and use some Blue Locktight. You shouldnt have any problem Breakin it loose w/ a wrench.

 

I see this topic on alot of boards, and I always answer the same way.

Use (2) sets of the stock Fel Pro exhaust manifold gaskets. Install them back-to-back, so the metal side on the gasket is facing the headers, and the metal side of the 2nd set is facing the head.

I've NEVER had a leak doing it this way. I've made more than a few believers after convincing them to try this instead of dropping $50 for a copper or alum gasket.

I use standard bolts, but I tend to use the one's that have 7/16 heads and a larger "shoulder" around the bolt. Sometime you'll have to "make" some room on the header tubes to let these bolts screw in, but usually no big deal. I use red loctite, and I've never had a bolt back out.

In fact, with the headers on my TPI IROC right now, I thought I had an exhaust leak when I first installed them...turns out it's actually QUIETER under the hood with the headers than with the stock manifolds, and the ticking is freakin' injectors!!!


And exhaust leaks WILL cause weird idle problems sometimes. Closed loop OR open loop.

As for the collector to Y-pipe gaskets, I'm using the deadsoft alum Flowtech gaskets ( came with nice bolts too for $20 ) and they work great, although since they are so thick, they can be a pain to get on. I let my exhaust guy fight 'em since he was modifying my stock cat to work with my headers and Y-pipe.


HTH

 

Try stage 8 headers bolts