Had the new motor in car and up and running since Christmas and just did logging so the tuner can begin to fine tune. He said it looks like I have an exhaust leak on both sides. If I do it would be in three possible locations and my biggest guess would be at the collectors of header as I have kooks with the slip on connector and band clamped it. The headers and and o2 bung on both sides with a plug(for a dual wideband setup aproximately8-10 inches from the collectors are the only points that could give a false reading the way my system is configured. I felt collectors and bung area by hand at idle for blowing and nothing but have not had it back up on the jackstands since except to change the oill and filter. Any tricks for sealing the collectors and was wondering if smoke might help see if its pulling air in. I also did check my header bolts again at oil change and all was still tight. I have earls header gaskets. Any suggestions would be good. Ive read that putting some tin foil wrap around exhaust helps seal the band clamp and have heard of others getting temperary results with copper rtv. I guess first I would like o confirm were the leak is and go from there. They are brand new ac delco o2 sensors also. It definatley is rich at idle(smell) but pulled a plug at oil change and it looked ok. I do have logging software and no codes have tripped and I am very ignorant with all of it and what to really look for or moniter. My egr and air have both been deleted in the tune and blocked off.

 

Is the tune set up for wideband as this would have us believe?

What is the O2 part number? I was not aware that Delco (actually Standard made them) had a wide band O2 for this application.

Could that be the problem? The readings stay lower than the band is set up for giving the PCM the wrong indication that it is lean and so it does what it can to fatten up the mix?

IDK just asking the question. I am certainly no expert. But then I don't see what it could hurt to simply do research at this point and not even have to get your hands dirty.

 

Sorry for the confusion. I have two narrow band o2 in the cooks headers(ac delco) then back 8-10 inches is the bungs with plug for the widebands(havent installed them yet). Pretty much I have the shop I work on the car 15 miles from my house and only can get an extra hand at odd times so hard to have someone hold a rag over exhaust tips or rev the motor for me. I know some people suck seafoam in a vacuum line but with new motor dont know if it would smoke out the exhaust leak as supposedly much of the smoke is from the carbon buildup. Ive seen a person use tranny fluid in similar way. My point is I have fresh oil in car and cant afford to drop the oil at this time as ive recently missed a full month of work with gallbladder infection and need to make the most of my time as well as limit any rich condition and washing down the cyllander walls. The o2 bungs will be simple to spot a leak but I dont think its my problem. The headers would be hard to see a leak or feel a leak but doesnt sound like leaky header gasket. Three sides of collector is easy to see and feel but the top not so much. I am assuming its at the collector and if so need advice on how to better seal that. I also dont know if there would be any other place in the system that could mess with o2 reading(like a vacuum line or pcv). Even with help I have an x pipe so not sure how well a rag in exhaust would help. I guess might be enough. I can take the exhaust apart at the x pipe and if I have no luck when I get it back to the shop thats what I will do. I have bigger problems now probably as car started last night and didnt want to idle and progressively got worse until didnt want to run at all. It was 22 degrees out so not sure if something froze up or the few miles I have on it a ground or connectiong worked loose or burnt wire. Was dark and didnt have time to start troubleshooting.

 

Try unplugging one of the 2 pre cat O2s and see how it runs. This forces it to run in open loop. If you need further explanation I can. It helped me when I had a wiring issue that made the engine progressively run worse and worse.

And just one suggestion. If you write more than a few sentences, break them into paragraphs so it's easier to read. Your last 2 posts are killing us.

 

Im the king of run on sentances lol. Those are me holding back too. Hard to space on the phone but will definately do better. I know I can with periods..............,.............. ... I only have the front o2 as the rear is eliminated. Im thinking my starting issue is related to not picking up fuel as well as it used too. I replaced pump and guage is all over the place so will add gas and see if it was a pickup problem with the no start issue as didnt find any loose connections but battery ground was loose.,............... upon first start up I was running without the maf and it was even richer then. ....... Imthe tuner adjusted the tune for 50 psi fuel pressure rather than the 49 he guessed at and that also seemed to run richer at idle. ,......................... I should have a chance to get under it tomorow if I get it running

 

Got it running again needed more fuel as isnt picking up like it did before fuel pump change as well as eradic fuel guage reading..,......... Was able to get it into shop and was able to stuff enough rag into exhaust to restrict the flow pretty good but didnt feel or hear any leaks at idle...... I did find my throttle body was pretty loose and tightening it up seemed to help........ I disconected the o2 sensor but didnt drive it like that (was still rich but before found the loose tb).......... will run it some tomorw with o2 unhooked given it doesnt snow .............. I gained some power as she was spinning the tires on a 35mph roll start and pulled hard.,............ I pulled two plugs and pass side looked good and driver side was black.......... my plugs are 2 stages colder and bigger gap in rings for the n2o would this be part of richness? ............. what would I look for in my logs that would indicate exhaust leak or something causing the richness.......... I have retunes as part of my email tune so will be talking with tuner also but want to do what I can before I have him adjust things. ...... thanks for the help and any other suggestions or advice would be greatly appreciated.

 

You should look at the passenger side O2 signal live to see what it is doing.

My passenger side O2 wire and 2 others were burned completely. The vehicle never threw a code but what happened was the PCM saw it as running rich and kept pulling fuel until it got so lean it could barely idle. It would jump out of closed loop then back into closed loop and start the whole circle again.

Just FYI, my wires were run down the passenger inner fender covered by protective foil over wrap was too close to the headers that I installed a year earlier. It took a year to burn through the wires.

In your case the wires (could) be shorted almost to ground making the O2 signal look like it's running lean and the PCM is fattening up the mix. This could be why the programmer thought you had an exhaust leak.

Look for a bundle of wires running down the inner fender and pull the foil off to inspect them.

Once I forced it into open loop by unhooking an O2, there was 2 ways I found the problem. I first looked at the O2 signal and saw it was not moving. The second was to short it ground were it should have gone near 0 but stayed at the center bias voltage of .45. Once I saw both of those, I knew the wiring was the issue. I finally looked under the foil and found the O2, the purple wire to the starter and the knock sensor wire burned.

 

Thanks Speedy, I logged the car today not real sure what im looking for with normal o2 operation but both sides fluctuated alot and averaging .415(both sides close) they were hitting both sides of that often with most being .2 and .8. Im assuming the fluctuation above and below is what normal is but I dont know. It showed it was in closed loop the whole time (even when I did some full throttle pulls)..............,........., I pulled the plug on drivers side and it was looking good today................... I thought I could get under car enough to disconnect an o2 but couldn't so didnt run it that way............. I definately know the wires you refer too as I went back and forth how to run them with my headers. I will look them over when I get a chance and definately do more to protect them from cooking.........,........... if I get a chance I will stop by an exhaust shop and get their opinion if they hear anything or whatever as they are much more experienced and could rev it while on lift if need be.................... I will also expect to hear from the tuner in the next couple days what concerned him.