Engine - Emissions and Exhaust


Topics covered:

Mufflers and pipes (Includes aftermarket systems)

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From: Robert Dassler[SMTP:roadsiderob@hotmail.com]
Sent: Tuesday, December 19, 2000 6:49 PM
Subject: [D90] exhaust stud removal

A word of advise about exhaust stud removal. I have very good success by heating the cast manifold cherry red--but do not heat the stud red hot, let cool a little, then spray the assembly with WD40--the cast iron expands slightly and the lubricant will wick in. you can usually then turn the stud out with vise grips or a stud remover. If it is the right side manifold, it will probably have to come off of the car, the left side can sometimes be done in place. Do NOT heat the studs red hot. I do not know what material composition they are (they are not magnetic) but they become harder than drill bits if heated red hot. I deal with a lot of this and I have about a 95% success rate when using this method. Obviously, all safety precautions associated with torches and such need to be observed. Do NOT go spraying WD40 around with the torch still lit. If you do this with the manifold on the car, watch the fuel lines and other components.

Rob

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From: BROWN DAVID E (DAVE)[SMTP:debrown@srpnet.com]
Sent: Wednesday, October 18, 2000 8:12 AM
Subject: [D90] Headers

Only headers I've found in the US are Hedman Headers. Summit Racing (mail order house) 1-800-230-3030 has them for around $85 or so. Part number 39800. These are for a '87 Range Rover, but may work for the D90. There's other sources in the UK and Australia if you want to pay high bucks and high shipping. You can also have them "Jet coated" for around $300 but that's way too rich for my blood. (Jet coat is a high temp ceramic coating). I think the Jet Hot makes them lot's quieter.

Good luck, Dave... Doug Marbourg[SMTP:marbourg@lanl.gov] added:
Yes the Rangie headers are out there, and they will work for the D90...My pair should be in in about a month...Call headman directly (their service number, not the dealers) and chat with them.

The part number is: 39806 (I'm not sure if it's coated or non-coated)...If your still having trouble call Bill Rhoads at (505)471-3888...He'll give ya' a screamin' deal on them too!

--D

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From: Bruce R. Bonar[SMTP:brbonar@wenet.net]
Sent: Thursday, January 06, 2000 8:46 AM
Subject: [D90] more on mufflers

Thanks Bill for the specifics on the parts used to replace the cats and muffler. (see Bill's post below in Catalytic Converters section, ed.)

For general information Flowmaster makes a muffler the same connections, width, and thickness as the "40 series" used by Bill but has a somewhat less aggressive sound, especially inside the vehicle. Part no. is 42551. It is 3" longer.

Bruce Bonar
94 D90 "Spot"

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Catalytic Converters

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From: Bill Ritchie[SMTP:billnsandi@kingwoodcable.com]
Sent: Monday, January 03, 2000 1:23 PM
Subject: [D90] Cat problem fixed finally!

I finally decided to take the D90 ('97 model) down to a local muffler shop (Meineke Discount Mufflers)and have the bent catalytic converter replaced. When they cut off the old cat (using a slick pipe cutting tool) it was full of small bits of the catalyst broken into about 1" cubes. They cut out the converter so that the existing O2 sensors stayed in place on the exhaust pipe both in front of and behind the Cat. The new cat was similar in shape and size (slightly smaller diameter) and when welded in place was actually tucked higher in the undercarriage. The part number for the Cat from Meineke was:

28814 (MAR) Converter 705 - cost was 135.00, free install!

During the install it was noted that the muffler was full of pieces of the inside of the Cat. so it was replaced with a FlowMaster muffler. Direct replacement part was:

42541 Flowmaster

The end result sounds pretty aggressive. Deep sounding idle and nice rumble when accelerating. It is moderatly louder than the stock exhaust. All this together was still about 1/5 of what the dealer wanted to replace the y-pipe and cats all together.

Bill Ritchie
'97 D90 ST AA Yellow

Neil (94 D90 #1092) added:
I also have the Flowmaster. Sounds great but can get a little overbearing at around 2500 rpm with the hardtop on. Now that the roof is off for the summer, i really enjoy the sound. It actually sounds like a V8 and not like a sewing machine anymore. Price was right too, about $185 installed.

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From: Jeremy Bartlett[SMTP:bartlett@slip.net]
Sent: Wednesday, July 26, 2000 4:34 PM
Subject: Re: [D90] Catalitic converters

Chris \"V\" wrote:

> There called O2 sensors, but if you rig is running properly the cats have
> very little to do in the way of cleaning the air.

I admit to reading this thread a bit late in the game but will add that, tehcnically, this is not exactly the case.

HO2s (heated O2 sensors) come in 2 formats on D90s: 1) ODBI '94 & '95 2) '97 OBDII.

In the OBDII variation there are 2 post cat sensors that are placed to monitor cat performance; removing the cats will trigger MIL illumination based on the post cat HO2s on board tests.

Regardless the pre cat HO2s are used in all models as instantaneous fuel trim controls in closed loop (after initial warm up and anything other than WOT). The catch is that the fuel system is not set to run at a fixed stoichiometric ratio. It is actually cycled rich/lean based on HO2s input. This is done because the cat needs a variation in rich and lean to operate in both hydrocarbon and NOx reduction modes. Disconnecting the HO2s will default to a run rich condition (rich is safer for the engine than lean). Bottom line is you might pass emissions with removed cats because the engine is fundamentally fairly clean (I know at least one vehicle that has a cat missing that has passed). However, you may fail emissions and you will certainly fail the visual if the tech doing the test does a proper visual. You will almost certainly fail with removed front HO2s regardless of MIL illumination issues.

Jeremy

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Oxygen Sensors

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From: Chris Velardi[SMTP:tchris@freewwweb.com]
Sent: Friday, January 28, 2000 4:18 AM
Subject: Re: O2 sensors

Try www.vertucciauto.com or call 203-269-2323 ask for Joey "V" we have been working on the the 4 wire replacement

Chris "V"

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From: A. P. "Sandy" Grice[SMTP:rover@pinn.net]
Sent: Tuesday, March 07, 2000 12:27 PM
Subject: O2 sensors

NOTTHD@aol.com is having trouble with the oxygen sensors and Troy Wilson gave a nice dissertation on their function.

You need a M-12 sensor, that is, metric 12 by 1.25 threaded. The Lucas 3LS, heated titania sensors are made by NTK Technical Ceramics, apparently the *only* manufacturer in the world now doing the 12X1.25 size. These are the *three wire* sensors used on OBD-I and previous vhicles. Try any of the following Nissan parts: 226A0-40U60, 22690-88G01, 22690-61A00 or 22960-)M210. All are made by NTK and differ only in the terminal plug. Oh yeah, they differ in price: the Nissan one is around $60.

Now if you have the OBD-II system, you need a *four wire* sensor. My crossover number is Nissan 22690-85E10, though I haven't tried it yet. The best price I've found is around $77.

The curious thing is *this is the exact same part* save for the terminal plug. Go figure why Rover charges almost three times the price...and that is from after market retailers...direct through the dealer network is even more obscene.

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From: Michael Nix[SMTP:mikenix@flash.net]
Sent: Wednesday, April 29, 1998 5:41 AM
Subject: O2 Sensor Replacement

Hi Everbody.
The Check-engine light came on recently on my wife's 96 Range Rover. A trip to the dealer told us that the engine had a slow oxygen sensor. Instead of paying the $275 from the dealer, we got one at a Nissan dealer for $90. Thanks to the cso-digest for the part number: 22690-85E10.

I spliced the Range Rover connector on to the Nissan sensor and it fit perfectly. Three out of the four wire colors even matched-up.

I am going to replace the other three sensors and then make another trip to the dealer to get the light reset. Hopefully the check engine light will stay off for a while this time.

Sincerely,
Michael Nix
1996 Range Rover

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Heat Shielding

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From: GEORGE SAITANIS[SMTP:Geoland.range-rover@worldnet.att.net]
Sent: Wednesday, November 08, 2000 7:11 PM
Subject: [D90] Re: Headers wraping

Doug,and others.Two years ago prior to my trip out west to death valley I decided to wrap my manifold and down pipes up to the cats with header wrap to keep the heat under the hood lower.

The result was the second day while 4wheeling the hole in the rock trail in UT,both pipe welds between the cats and the manifold came apart as if they were cut with the sawzal.

The heat withinn the wrapped pipe was too much for the welds to hold.
The ambient temps were around 100 F.
You might get away with it if the temps outside are less than 75 F.
I also had my manifold crack a year later as a I am definately sure the wraping had some thing to do with it.

Think before you decide to do it.

George Saitanis

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From: Chris "V"[SMTP:tchris@freewwweb.com]
Sent: Monday, May 22, 2000 7:57 AM
Subject: RE: [D90] heat insulating plate above exhaust pipe

Ivan, I have put in a heat shield above the muffler and the temps get dramatically lower when one is installed. I would never even have thought of it until I installed the "Flow Master" muffler . The directions that came with the muffler claimed that because the muffler flow so much freer than stock mufflers exhaust (and the heat associated with it is moved out of the engine compartment (exhaust manifold, pipes and cats,) and more is transmitted farther down the line to the muffler . The muffler can handle the excessive heat but heat by it's nature travel up and in our case that is directly under the center console. They recommended that heat shields be installed in all situations , and in mine I could have cooked a small meal (very small) in the stock console. So I crawled under and took some measurements, cut up a sheet of aluminum to cover as much area as possible above the muffler with out interfering with any other moving parts. Their happen to be two or three holes already existing in the frame (one for the muffler hanger the other unused) When installed the temps dropped low enough to keep chocolate in the console now. What it does, is it keeps the under vehicle air currents carrying the heat away.

Chris later added:
Mine is a '97 the only things that come close to where you need the shield is the transfer box and the hand brake off the rear drive shaft . These are the places you have to notch around.

__ I I_
I__I cut plate like this

Chris "V"

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