exuast leak......... help
 

Alright, I just installed my JBA headers two days ago. I paid a shop to do the work as I have no time for the install. Yesterday I noticed a very rough Idle while cold but once it warmed up it would idle fine. I then noticed today a put put put sound coming from under the hood. I figure an exuast leak. I take a peak and see that the EGR Tube had been melted away leaving a large hole. I can see the exuast coming from the metle tube where the EGR tube runs. Is this what was causeing my rough Idle and is that tube suppose to be rubber or metal?

i just had problems with EGR and from what i was told EGR really only has to do with emissions and gas mileage..

EGR should never be commanded at idle so it should not make your idle rough. However, an exhaust leak can affect the exhaust mixture to the oxygen sensor and that can influence the air/fuel ratio.

I would also check to make sure that the plug wires are properly routed and seated on the plugs. They had to have been removed during the header installation.

The EGR tube is steel and the short hoses that tee off of it to the DPFE sensor are silicone rubber.

so that would cause the rough Idle. It only happens in the moring when the engine is very cool throught the rest of the day i can leave it for 6 hrs and come back and it works great except now for the PUT PUT PUT sound comeing from the drivers side. The tube was resting on the header pipe and melted away. Would puting flex hosing on fix the melting issue? I guess it goin back to the shop tommorrow so I can yell at them. I am in the army, I love to yell at people.

I'm having a hard time visualizing this. Maybe we're not talking about the same thing.

On your 2001 4.0L, there should be a steel EGR tube that has a fitting screwed to the driver side header collector. It should mount and function exactly as it did when it was mounted to the stock DS cast iron manifold. The short rubber tubes should be a long way from the header.

nope it was literally resting on the header.............. with some heat sheilding cloth..... I just replaced the tubing, and re-routed it far enough away to protect it. I test drove it and it was still very hot, is this normal? it has about 3-4 inches of clearance from the header now.

Yes very normal, EGR is Exhaust Gas Recirculation so it should be quite warm... When I did my headers I had to bend my EGR pipe a little to get it to work, however I dont quite understand how yours could get a hole.

k, fixed the tube, but still get the cold Idle problem any suggestions? goes really hi then sounds like a harley. jumps from 500 to 2000 rpms. then settles down to idle fine, what could it be?

Try disconnecting the battery for 20 minutes to reset the cumpooper, if that doesn't do it I would look at the IAC (Idle air controller)

where is the IAC controller at?

On top of the throttle body under the 4.0 SOHC cover.

so should I try and clean it or just replace the IAC? also if i replace it how much would it cost me? Is there anything else you could think of that would cause this problem with the Idle?