So after extensive teardown and repair on my new to me ‘06 STR, to fix numerous crap like the hose under the supercharger, coolant hoses, pumps, bad connectors, no AC, leaky exhaust pipes, and a host of others, ive been haunted with a recurring lean Dtc for both banks (p0171 and p0174).

Replaced all o rings on all vacuum lines new gaskets all the way down to the heads but still throw the lean code.

So yesterday I started looking at the MAF and I thought I found it. Today I tried yet again to fix It.

I came to look at the MAF by accident. I had Started the car with the MAF unplugged and got a MAF dtc. But later on I forgot I had done that so when the codepopped up is started troubleshooting per the IDS instructions.

First test was-to see if theres 12v at the w key on and maf unplugged. There was.

Next was to check for ground on pin 2 with key on. Supposed to be less than 5 ohms. Im getting 10. There was something weird going on. With key on I get 10ohms. Key off it slowly drops then goes to 0 ohms. Key on it goes back to 10. Repeatedly.

Nest test was to check for shorts to ground and I found a higher resistance than specd but I forgot to disconnect the ecm so that may have been it.

I recall doing a module reprogramming where I may have corrupted theECM. Goin to try a hard reset then reprogram the ECM.

I successfully reprogrammed the ecm and a couple of other modules. Discovered my car was set foe the base v6 suspension. Not any more. Im at the str performance setting now. Also had the wrong tire size. Fixed that too.

So before I dug into disconnecting the ecm to check the wiring, i yanked out the wipers, the plastic cowel and the strut and cabin filter box and did another smoke test. First smoke test showed the exhaust leaking at the pipe off the passenger side exhaust manifold. The flared end was boogered up. Replaced the head pipes w cats, and o2 sensors. The reduced the wicked high stft and ltft on the passenger side. Was 20. After it was 10 for stft. Drivers side was 7.

So I did a second smoke test after fixing the exhaust and put all new orings on. Boom! FOUND IT!

All around the egr valv was smoking. And it looked like it was from the top cover. Unbolted it and sure enough it was wet with mineral oil that condensed on it. So I need a new egr. And gaskets. Also found out my lower egr tube gasket was wrong. Its center hole is bigger than the tube or the old gasket. I will have to figure the part numbers.

Enjoy the pics

 

Pics

Trying to work the software. Looks straight forward

 

More

New pipes and cats

That was scary

Smoking from between the upper black piece and the aluminum and also from the lower aluminum to cast iron. Still was a little wet when I removed it

Not sure if these can be repaired

This gasket had a larger hole than the original in next pic

 

Few more

Whew!

Not sure why I got this. But it seemed to be fixed later on

It showed weird setups. A manual?

 

Excellent news! Great troubleshooting!

Fantastic that you kept going after fixing the first leak. Would you say the second leak was smaller and didn't show up initially because all of the smoke was escaping from the bigger first leak?

 

Ya the passenger side exhaust flange was muckered up so smoke was coming up there pretty strong. And the egr is right there. I wrapped the tube with a heat shield earlier so when the smoke was billowing up by the egr I couldn’t tell if it was from the egr or from the flange.

It was both

 

Did you make a smoker or buy one.....i want one myself, but know zip about them..thanks

 

I bought one off amazon. Funny bc I was going to make one too but shoot, for the parts involved it was easier and probably safer just to buy one. I looked at the reviews on amazon and got this one.

 

Couple things, i looked at tht smoker on amazon and damn that thing smokes better than ours at work. May have to buy it.
2. Dont ask me why but we always get smoke from the egr valve even when new. I remember there being a egr cleaning cycle but no longer there. It would stutter the pintle to clean deposits and help to reset dirty valves. Im reall happy we no longer deal with egr valves and they use passive egr function. Although thats a bit problematic for cats coming apart and sucking the pieces back into cylinder trashing the engine. Have never seen on a jaguar but i know its a problem for nissan engines.
Good stuff, at least you understand that this stuff is a process and many times you give a quote and repair and have to keep going afterwards with issues like this

 

When I first removed the EGR, I was determined to "fix it" so I started to removed the top bolts and take the pieces apart. I soon realized the device is not "take apartable" (a word I invented just now) because the sealing part is pressed onto the shaft and I was sure Id break it so I left it untill I got a new one (in case I really need to use the old one.

From the disassembly that I did do, I saw that the black plastic (or maybe hard rubber) part that is between the top solenoid cap and the aluminum cooling hose piece has no separate gasket. it seem to rely on the the plastic/hard rubber piece to make the seal. Problem is that black piece has two cylindrical metal inserts in the bolt holes that act as spacers. It did not appear as if those spacers could fit inside the bolts to allow the plastic/hard rubber piece to crush to form a seal. It looked like the metal cylindrical spacers would be sandwiched between the cap and the aluminum piece so it if shrunk due to heat and compression. it would never seal right.

I wanted to try putting a layer of indian head gasket shellac in there and see it that would work to seal it but i didnt.

Replacing it will be on friday when the new valve comes in so may i will play with the old piece after that.

 

If indian head cant seal , nothing can.....that stuff is good old school sealant...when i worked on heavy duty trucks, Caterpillar made a green sealant that was unbelievable, by itself or as a glue, never failed me

 

Im getting a lil nervous. Ordered new gaskets from terrys jag but they still havent sent a shipping notice. I so wanted to do it this weekend but its not looking good. I usually get stuff from my other sources in 3 or 4 days. I hope I get the parts on Saturday

 

Thanks for this post!

 

So with the knowledge that my new EGR valve will be delivered this friday but the gaskets from Terrys Jag still being picked, I re-ordered the gaskets from a US based jag dealer and paid for overnight shipping ($15 extra) to get them here on friday. I am determined to make this work!

 

I see from the gash on your thumb that you have also made a blood offering to the Car Gods, who will hopefully help you in this undertaking...

 

ya, that wasnt really a voluntary offering. more of a quid pro quo type of deal. Big hands in small sharp spaces equals a blood letting.

On the other hand, looks like my immune system is working perfectly as there have been no infections since packing the open wounds with dirt and grease from who knows where!

 

I know the big hands dilemma well.....i always get tore up working in vicinity of cooling fins... radiator, oil coolers and the like....those cuts always bleed like i cut my finger off....and sting like hell

 

Hi,

where did you plug a smoke machine to find my bank1 bank2 leaks, I also bought a smoke machine, but I’ve connected it and smoke only went from air filter box. So I wanted to know where to plug it, maybe I do something wrong.

 

Great question. I had to try a couple of things. I too had a ton of smoke pouring out of the air cleaner and air intake duct by the radiator. So I used duct tape on the inside of the air cleaner box lid covering the air tube hole that goes to the tube to block it.

I doubled up the duct tape to slow the leak. M

i injected the smoke in two different places for 2 separate smoke attempts. First I disconnected the hard line from the pcv valve and shoved the smoke machine hose into the vacuum line's hard tube quick disconnect that came off the pcv valve. That worked well. I saw there was no leaks in various places like the vacuum line quick disconnect at the brake booster but it was leaking slightly at the end of the line where it went into the throttle body elbow fitting. I had replaced the o-ring in that fitting at the throttle body elbow so I knew it had a good o-ring but it still leaked some so I removed the tube to look at it it, After I removed that line from the fitting and I saw it was grooved from rubbing on the brass shell of the fitting. Pic below. So I spent some time with 800 grit sand paper polishing out the groove in the plastic line by wet sanding using 800 grit up to 3000 grit until it was smooth again. I used calipers to make sure I didnt reduce the diameter too much.

the second time I injected the smoke into that short hard line at the disconnect shown in the attached photo


This is the vacuum line that goes to the fitting at the throttle body elbow. It was leaking slightly. Its grooved so I wet sanded it smooth on both ends so it would seal. It worked!

I ran a vacuum test and had a steady 17inches of vacuum and it behaved well. No bad valves or major leaks

Heres where I injected the smoke the second time. You can see the rubber 90 degree elbow on the hard line

Anyone know why the replacement egr lower tube gasket (bottom) has a bigger opening that the original gasket? The tubes hole matches the smaller hole but the replacement has the bigger hole. I want the right gasket. Also does it natter which way its installed?

 

That brake booster line where it goes into the tb elbow is the number one cause of vacuum leaks on lean engines by far. The egr port is right by it so it gets nice hot exhuast to cook the o ring and lock ring for that tube. I have several different new tb elbows i need to get on ebay and am in the middle of cleaning out my collection of new and used parts in my shop. I usually put 3m silicone paste on this pipe to easy entry and help provide a little better sealing