Happy Holidays forum members. A few months ago I began a thread describing my 03 STR throwing a CEL with "Restricted Performance" (bank 1 and 2 lean). Possible gremlins were: Exhaust leak before the cats, MAF sensor, and vaccume leak. The indy mechanic/exhaust shop determined the EGR to manifold tube was leaking and possibly the exhaust manifold gasket to boot. Picked up an EGR tube plus gaskets for $120. Mechanic popped off cabin filter box (under hood passenger side) and replaced EGR tube. The failed tube had rotted away mid way on the corrugated portion that allows it to flex. The underhood exhaust leak noise was solved but she still threw the CEL w/restricted performance w/both banks lean code. Due to focusing on the EGR tube, I didn't relaize that one or both Magnaflow cats were rattling. Purchased one from Summitt ($113) with the hope that one not both were toasted. Yesterday the shop replaced the passenger side cat after learning that cat had melted. They feel the drivers side melted too. The mechanic also feels; despite the EGR tube replacement, the exhaust manifold it attaches is leaking too because there is an exhaust leak noise for a short time after cold start ups that stops after warm up. Looks like the passenger exhaust manifold gasket will be replaced too. I'm ordering another cat for the drivers side as a means to start fresh. All in all, the leaking EGR tube likely raised exhaust gas temps. to the point of melting the cats. Though replaced 3 months ago, faulty O2 sensors will cause the same. Question to ya all: Will Lincoln LS exhaust manifold gaskets interchange with Jag? Happy Chanukah, Merry Christmas, Happy kwanza, and Happy Holidays to all.

 

It seems to be yes. When the set of LS/S Type headers was being passed around we had a lot of discussion on this. The exhaust manifolds are built slightly different but the bolt pattern and port size are the same. Brutal did mention that the SC and NA cars use the exact same heads which was surprising to me.

Sorry I don't have a Ford part number. Hopefully this Fel-Pro gasket would fit? The reason I can't say for sure is it is only listed for the LS 3.9L.

FEL-PRO Part # MS96925
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and they need to look closely at the manifold because theyre more like to crack than have a gasket leak, especially the early V8's. The 4.2's not as much

 

Thanks clubairth and brutal. Brutal, can a rusted out EGR tube cause the cats to melt? It had completely opened up mid pipe on corragated (flex) section).

 

Thanks clubairth and Brutal.

 

Per your PM Bfg. think about this. the egr pipe cracks from engine flex(think bending a coat hanger constantly) and now induces air into to exhaust stream upstream from the 02 that reads air to fuel ratios. 1 side only unless you really do have a exhaust leak on both sides. The 02 THINKS the engine is lean so adds fuel which in reality creats a overly rich condition but it thinks its okay. Now a lean condition in the cylinder torches pistons(high cylinder temps and cool exhaust) but its a cool exhaust stream since theres no unburned fuel. a rich condition in the cylinder is cool temps, but rich still burning fuel in exhaust is very high temp. And when its still burning in the cats they can glow red hot(and melt)
So the short of it is that and exhaust leak makes the ecu think the engine is lean when its not and richens up the mix to get the correct afrs.except that now theyre too rich and burning in the cats and torching them. This is another example of things that can be relativly minor creating additional problems and more expensive repairs. Like letting misfires go. they dump unburned fuel into the cats too and poisen them causing them to eventually though P0420 430 codes for cat inefficiency before there time. This is a long answer but an explanation of the cause effect

 

Totally agree with Brutal. If you notice a small fault or change in the vehicle developing, get it fixed. If there are two components the same, and one fails, thoroughly check the other: the probability that it too is in trouble is quite high.

Remember, prevention is better than cure, and usually cheaper.

cheers,

Languid

 

10-4 brothers...prior to finding rotted EGR tube and melted cats, noticed black about exhaust tips. EGR tube was replaced plus pass. cat. Drivers cat replaced next week. Be well and "Stay thirsty my friends" (Dos X's Beer commercial).

 

Picked up the car and...Wow! I haven't realized how much the power was down till the passenger side Magnaflow cat was replaced. The EGR tube likely failed a while back, causing too lean a burn- melting the cats. She's throatier at start up and power has noticeably increased. The replaced Magnaflow cat's internal honeycomb matrix had melted to the point where it no longer was connected to the body, clogging and banging around in the body of the cat. I'll order the drivers cat on Tuesday. For now, a hard re-set of the ECU. She'll be dynoed after the drivers' cat install.

 

Just got the news my driver side cat is toast...Not sure on the rules, but I was able to the get a pair of magnaflow high flow 59975s from an ebay seller for $230 shipped, plus 2% cashback put 1% cash back from ebates.com or a net of $223.10. If someone wants to PM I'll them the sellers name. Will have the mechanic check out my egr...

And to think I was getting cocky...I thought to myself what the heck, I haven't spend a lot of $$$ on the Jag this month, let's do the trans fluid change! Mistake...lol

 

Glad you got the solution in your grasp Seth! May as well start fresh with new cats on both sides eh? No sense just doing one of them, based on what has been discussed in this thread. Some great info from the forum members!

That's a pretty good price for cats too bro....she'll be ready to roast those rear tires in no time!!

 

Now you just need an LSD to put all that power down.

 

Hi guys. Thanks Bacardi, Chris, and Mike, for your support and your wisdom. Waiting for the drivers side $113 Summitt Magnaflow cat to arrive. The new passenger side did prove a modest amount of power had been rightfully withheld by the ECU. I can only imagine how it all will come together when the drivers side cat makes it all come together. Bacardi, was it a Magnaflow cat that melted? Mike, in regards to an LSD, one of our members "R" now wears a Quafe LSD that IMO was purchased and installed at a suprrisingly low cost. I'll let him bring this to all our attention. Firm 12 second "R"'s, without lowering tire pressure or tossing the rear seat and spare out of the car are just over the horizon. Hope ya all enjoyed the holidays and happy new year.

 

Yup, he sent me the videos of it I am tempted to put my car on a truck and transport it to him!

 

Do it Mike. Did he let you in on the TCM flashed with an XKR file? Gotta really hand it to him for his effort in STR mod-development.

 

Yes, I should show the vid that he sent me where it shifted at 6k in first! That alone makes it worth it!

 

Mike, if possible please foward the vid. Otherwise I believe the results.

 

No, OEM did...

My new year will NOT be happy until I find out about this low cost LSD...

 

$800+ for Quafe LSD. $600+ for install. Gives me a hot rod just thinking about it.

 

Still a little too pricey; I don't see the value...Now a raised redline makes me drip at the tip...