New exhaust now engine idle issues

[Kermit]

Just had the truck inspected put on new exhaust and it's running worse now than with the old exhaust. The engine is surging or loping is what the mechanic said. Put it on diagnostics and came back saying egr flow issue (just replaced egr less than a year ago plus some vacuum line and that crazy leaking elbow), 2 heated oxygen sensors and misfire cylinder 6. Went to the cylinder page on the diagnostics machine and all cylinders read 0 including 6, however 4 was fluctuating 0 to -12 to -15 back to zero. Mechanic feels it's a stuck egr or vacuum leak somewhere... I lifted up the heater hoses and the idle dropped so low for a sec I thought it was gonna stall, but it recovered. Parked idle at 600-700 rpm, smells like it's burning rich even tho the diagnostics said a couple banks were lean (Sry I can't remember which 2 he said)... The surging is worse when it's in gear, stopped at a light u can feel the car rock with each surge and it freaks me the hell out... Trying to get a video to load of the engine but the forum doesn't permit mp4 videos so trying to load to drive to get a link to share. Any thoughts?

 

[Kermit]

OK here's the video link. The beginning of the video the truck was in gear, then u hear it in park.
https://drive.google.com/file/d/0B_pkIhhcojJoTzhzTmFBMkx1cE0/view?usp=drivesdk

 

[docraymund]

Try feeling the egr pipe when first starting the truck. If it feels warm, the egr valve may be faulty.

 

[Kermit]

Felt one of the tubes going into the egr valve, one that's supposed to suck air and it felt like it was vibrating, no suction really at all. My mechanic is trying to tell me, from his research, sounds like it needs an intake gasket. He says that's the one thing that would cause all those codes. Which i don't get cause it ran fine before the new exhaust system

 

[Kermit]

Are there any kind of temporary fixes you can do for a bad intake gasket without tearing apart the whole top end of the motor?

 

[1955moose]

Wells here's a dumb question? If changing out Exaust made it run rough/ bad, make them figure out what they did. I wouldn't try to fix it yourself if they broke it. The tough part is you proving it ran crappy after they took a wrench to it. Is the port for the egr through the intake clear? If it's clogged it will cause all kinds of havoc. Usually pulling the egr valve and running a coat hanger along with carb cleaner in and out will break up carboned up passages. Problem is in my experience most Exaust guys aren't very high on the food chain. They do one job, usually involving a torch and that's it. My appolagies to Exaust guys/ girls that are techs as well, so you might have a little struggle on your hands . Keep us posted, we love a happy ending.


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[Kermit]

Thanks for the reply. This wasn't just an exhaust guy... 30 yr seasoned mechanic that came with good references who also consulted with a long time ford mechanic to eliminate possibilities... He wants me to bring it back so he can put the vacuum gage on it to confirm his thinking... He suspects the vacuum leak is by #4 cylinder which is why it was reading 0 to -15 on diagnostics without throwing a Miss error code. Gawd this is sooo frustrating...
Question, how long do you think it should take to perform an intake gasket replacement of that's what needs to be done? And do those gaskets go bad that often?

Just curious but does my video work for you guys?

 

[1955moose]

Kermit, I'm assuming it's a first edition 2 valve 4.6/5.3 motor? That's the area you posted it. Always a good idea to post year, motor, two or four wheel drive. But anyhow I looked it up, and it's booked at 6.4 hours to do both upper and lower intakes, plus parts. So assuming an average of $100.00 to $150.00 an hour, your looking at least $640.00 plus at least another $75.00 to 100.00 in parts. Gaskets, coolant etc. thing is your probably going to want to change manifolds as their plastic and do crack. So anywhere from $600.00 parts and labor if you get a killer deal, up to about $1000.00 if you change everything.


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[Habbibie]

Curious what in the exhaust was replaced?

Is it an entirely new system from the exhaust manifold all the way to muffler tip including new resonator & cats and mufflers?

Personally I wouldn't go tearing up the motor yet, crawl under the truck and inspect the surrounding areas to the new exhaust pipes, make sure pipes aren't touching any wiring or vacuum hoses, double and triple check the wiring harness for the O2 sensors, make sure they're screwed all the way down and the connections are secure.

 

[Kermit]

Moose, it use to say in my signature it's a 99 4.6 4wd. I didn't even notice it wasn't there anymore. And ur pricing is about right. He was in the 675 ballpark.

Habbibie, to my knowledge all that was replaced was muffler and tailpipe. Cat want touched. Someone else was helping to pay the bill so i haven't gotten my invoice yet. I'm under it tomoro checking the things you mentioned. He wants me to bring it back out monday Tuesday for a vacuum test (no charge of course). Thanks for the info.

Sooo can anyone tell me if my video link works for them?