Forgot to document the last pieces ...

So, Mitsu doesn't sell the exhaust down pipe for the '99 3.5L FED driver side. They DO still sell the 3.5L FED passenger side - the side with the flex joint built in. The early '99 3.5L FED version did NOT come with CATs in the down pipes, but the late '99 FED did as did the CAL version.

Mitsu's parts database is kinda screwed up. They have the listings and diagrams for the 3.0L and 3.5L CAL and FED all mixed up. It was a real PITA finally getting the correct PN for the passenger side pipe.

So, what I ended up doing is getting the 3.5L down pipe for the passenger side and getting the 3.0L down pipe for the driver side. We removed the bracket on the driver side down pipe that bolts to the bell housing - never could figure out what the point of that was - because it wasn't possible to bolt it back where it's supposed to go and dimpled the pipe just a tad to clear the bottom bell housing bolt.

On the passenger side down pipe, we cut the driver side leg of the Y off about 3" back from the flange, extended it just a tad more than 1" and welded everything back up. The passenger side down pipe fit perfectly and came out under the vehicle exactly where the 3.0L did so all the exhaust hangers, etc. all remain in the factory locations with factory hardware.

So, AFAIKT, there is a width difference between the 3.0L SOHC and the 3.5L SOHC. Not much, but some. We chopped the crap out of original 3.0L exhaust to get it to fit - a lot more than just extending one pipe 1". This was very near just a bolt it and as long as one had a welder it could be done at home easy.

The dimple of the driver side down pipe and removing the bracket would not be necessary on a A/T model. These were to address minor differences underneath between the M/T and A/T.

BTW, the OEM pipes come with all the heat shielding. Which I was REALLY missing there towards the end of the life of the 3.0L. Also cuts down some on vehicle noise.

Walker - in theory - is supposed to sell both sides. Both for the 3.0L and the 3.5L. I've been around and around with them for almost two years on this. In reality, though they list PNs for the 3.5L, what they actually sell you is the 3.0L pipes and they are NOT the same thing. The last go-around they admitted that they DO NOT sell the 3.5L down pipes and that is in fact an error in the catalogs.

So, OEM is only option short of having a custom setup from the manifolds down. I did check into this and it was going to cost at least twice what the OEM pipes were going to cost including the $75 the shop charged to extend the Y leg.

The exhaust is back to factory parts all the way to (and including) the elbow that the rear O2 sensor screws into. Runs a lot better with the stock CAT, too, for whatever reason.

I changed to the Flowmaster 'SUV' muffler (52455) from the original 50 Series. The 455 is 1" thicker but otherwise the same in dimension. 2.25" in/out. Flows just as well but is considerably quieter than the 50 Series I was running. Very nice on the highway and off road. Anyway, everything from the elbow back is custom 2.25".

Edward

Great info dude! This will save me some trouble, i am moving my cats from the down pipes and going mid 90's style on my '99. Converting to FED emissions so i'll be looking for pipes in the JY tomorrow.

Do you know if the manifolds are the same between the FED and CA model 3.5's?

The exhaust was a PITA. <img src="/forums/images/graemlins/frown.gif" alt="" /> Why Mitsu couldn't just make the driver side down pipe ... sigh. Let me know if you need pics of the mod. Keep forgetting to take some.

How are you going to get from 4 O2 sensors to 2 O2 sensors? The FED versions have one O2 sensor for and one aft of the one big CAT. CAL wiring is a good bit different from the FED wiring so you can't just swap ECMs.



AFAIK, the manifolds are the same between the 3.0L and 3.5L irrespective of CAL or FED as well as year. '97 through '05.

We checked and test fit both my 3.0L and 3.5L manifolds on my 3.5L and my old 3.0L. Identical. Remember the techs saying the manifolds are the same between CAL and FED and I remember the parts people saying the same.

Can't imagine them being different. There's nothing in the manifolds like emissions stuff and the '00-'05 FED design is the CAL '98/99 design.

Edward

I've already done the cat delete and as far as the ECU is concerned everything is awesome, I'd just like some legit stock Y pipes.

The CAT delete?

Yea, I was looking at Walkers again yesterday. God, what crap. <img src="/forums/images/graemlins/frown.gif" alt="" /> Those things can't possibly flow worth a damn. I can't believe they can't be bothered to mandrel bend those.

Edward

Yeah, my truck is a Cal emissions so it had 3 catalysts. The rear most one was removed years ago and it functioned more as a resonator in stock config and the ECU doesn't watch it. The other two however are monitored, they need to go because they rob a little power and one is in a bad spot for wheeling. I'm going to just a single unmonitored cat or maybe just a resonator back where the rear one was originally.


The headers from Australia look nice Pacemaker I think?

Ah. Ok.



Cool! I haven't seen these.

Pajero NK-NL 3.5L V6 TUNED

I presume these are the 'correct' ones. I'd like to know what they mean by bolts to the stock system. It looks like an O2 bung on the Y so I presume this replaces the entire front section with the flex joint. Not sure that's such a good idea. OR, this is the type that has the flex joint as a replaceable part and this bolts to the flex joint that then bolts to the CAT. Hmmmm. Wonder how much with the ceramic coating?

Edward

I took the Sport out weekend before last and ran into some serious over heating issues. Nothing really at the beginning of the trip, but when I got off road it just went straight to hell. I couldn't figure it out as everything seemed to be fine. Dang thing was even overheating going down hill which it has NEVER done. <img src="/forums/images/graemlins/frown.gif" alt="" />

The only thing I could think of was a fan(s) going south. Since then I'd been getting some abnormal temp behavior so I decided to replace both fans before we take off to Moab next week. I already had a spare assembly so I figured I'd rather be safe than sorry.

So, I spent most of the weekend replacing the fan motors. The spare assembly is an OEM Ford part. The original assembly was from Rock Auto - God only knows where it was made, but it wasn't in the US.

Anyway, I dropped the new motors in, bolted it back to the radiator and then dropped the entire thing back in the truck. Hooked all the wiring back up. Cleaned up a couple things and fired it up. And promptly blew both 25A fan fuses. <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> Checked the docs - the max for the Spal PWM is 30A - and slapped a 30A back in the secondary fan. That worked ok and then I realized that was my last 30A. I went through three 25A fuses with no luck. I called it a night at that point.

I got up the next morning, checked for shorts and found nothing. Figured I could make it to the Autozone without fans since its 6-7 miles but all down hill. Got to Autozone fine, picked up a bunch of fuses and a 30A breaker for testing. Slapped the breaker in and everything was happy. Been driving it for about 150 miles with no fuse issues.

So far, the cooling seems to be back to "normal". I had to stick it in 2nd for 3-4 miles pushing 4K RPM uphill to get it into the mid 200s. I haven't gotten it to get to 208 to kick in the secondary fan, yet. So, yea, 'normal'.

So, given that I can find NO issues anywhere in the wiring and the fan motors are working just fine, I'm wondering just how well some of these aftermarket OEM-like replacement fan assemblies actually work. I can tell the Ford motors draw more amps. Obviously inrush is significantly higher than my original fan motors. AFAIKT, the Ford motors seems to draw more air.

Anyway, yet one more thing that has to be flipping perfect for this to work without melting down. I hate projects that end 95% perfect. That last 5% just takes all the fun out of the other 95%. <img src="/forums/images/graemlins/frown.gif" alt="" /> With the new exhaust in and the cracked manifold replaced, it runs like a top. Quiet and smooth as glass. Tons of torque - a real joy to drive in the mountains - as long as I don't have to deal with Eisenhower Tunnel or Vail Pass. Zero problems in town driving. Rush hour stop and go in the 90s no problem even with the A/C on.

It would be educational to try this with the factory mechanical fan and shroud just to see if it worked better, worse or the same. However, since that would require some serious work - like moving the engine - I'm going to leave things as they are.

Maybe I'll readdress getting the Montero 3.5L ECM working in the Sport eventually when I have nothing better to break. Still suck, though, 'cause the 3.5L is absolutely awesome with the 5-speed M/T.

Edward

forgive me for asking a question that may have already been answered, but what did you do about the oil pan? I saw mentioning of modifying the stock pan, but I take it there is no stock pan that will allow this engine to bolt into a first gen 4x4? I may just modify the stock 3.0 pan to fit the 3.5.

I've got a 89 lwb first gen that is about to eat a con rod at 254K. I have recently procured a 3.5 sohc from a 2002 2wd sport. As far as I have been able to tell, This engine should bolt up to my existing 5speed and use my existing flywheel and clutch. It looks like the mounts will need to be modified by about 1/2 an inch. "I've got a guy" that can do a complete custom down pipe back exhaust for around $250 to $300 (he's REALLY good a that price too!) And I plan on megasquirting the thing as far as fuel and ignition.

DOes that about cover it? aside from the cooling issues you ran in to? I'm keeping it stock otherwise and it will just be a daily with a bit more oomph and 4wd to tackle minnesota winters. no serious offorading or hauling here. ALso, before you ask, I went with the 3.5 because thats all I could find. the 3.0s are getting so rare here. Plus, if you ask me the 3.0 is a bit underpowered for even a stock montero.