94 Pathfinder Lack Of Low End Torque

[4wheeldrivefun]

I have a 94 pathfinder vg30 v6 with an automatic. I seem to have a large lack of power going up hills and from a complete stop. Just wonder what would cause this. My transmission seems to shift just fine no hard shifting or anything.

 

Is there a transmission filter inside the tranny pan or something that gets cloged over time. My car has well over 200k miles on it.

[Precise1]

You have a 15 year old 3 liter V6 with over 200k on it and it seems to be lacking a bit of pep?? Damn!!

 

Ok, sarcasm out of the way, It could be everything from a tune up (plugs/wires, dist cap/rotor, timing) that perks it up a little to heavier oil to increase compression to a compression check and checking the exhaust for a clogged cat to diagnose larger issues. My recommendation is start with the tune up, but remember your truck has circumnavigated the globe 8+ times; if it is only showing signs of wear, pat it on the hood and thank it...

 

B

[87pathy]

have you ever messed with the timing?

[4wheeldrivefun]

yes i have messed with timing, I advanced it a little and i seemed to gain a little bit more power back.

 

 

have you ever messed with the timing?

[87pathy]

i have messed with mine quite a bit.

 

i have found that the factory setting gives the beset low low end.

[4wheeldrivefun]

I moved it back to the factory settings. Seems to be even less power. I find my self haveing to floor the gas pedal to make it up hills.

[Kingman]

That definitely doesn't seem right. I'd go with what B said, check for tune-up evidence and if it needs one, do it. Also check your catalytic converter for clogging. Run the ECU codes as well, may not show anything but it's free and only takes a few minutes.

 

[4wheeldrivefun]

I think my Catalytic Converter maybe cloged up. How common is this on high milage pathfinders 90-95?

 

I was going to just hollow it out, however dose anyone make a replacement pipe to just reaplce it straight thew? Or my other option is to go to a high flow cat. Has anyone done this? Will it throw a check engine light if i do this?

 

I have come to this conclution after doing a complete tuneup, spark plugs, plug wires, cap n rotor, fuel filter, timing belt, oil change. etc still has lack of power.

Edited November 11, 2009 by 4wheeldrivefun

[ChaosSaint]

cleaning out the throttle body really well put some pep in the step of my pathy, try that yet?

[Kingman]

I think my Catalytic Converter maybe cloged up. How common is this on high milage pathfinders 90-95?

 

I was going to just hollow it out, however dose anyone make a replacement pipe to just reaplce it straight thew? Or my other option is to go to a high flow cat. Has anyone done this? Will it throw a check engine light if i do this?

 

I have come to this conclution after doing a complete tuneup, spark plugs, plug wires, cap n rotor, fuel filter, timing belt, oil change. etc still has lack of power.

 

Cat pipes are extremely illegal because you are removing the biggest part of the emissions system (you know how people are these days...), but will not throw a check engine light as the oxygen sensor is up stream of the cat. If you have a shop make you a cat pipe, do not tell them what it's for, or they simply won't make it. Just tell them the size of pipe and the 2 bolt flanges, as well as the angles that they are positioned at. Unlike most rigs, the Pathfinder's cat flanges are not perfectly horizontal they are like / in the front and \ in the rear. If you truck was ran really rich at all, your cat is most likely somewhat clogged. After my Coolant Temp Sensor on my old '87 went out and dumped a bunch of gas in, the thing would not move. Almost no power, flooring it barely did anything, could not accelerate barely, etc. A Magnaflow high-flow cat cleared that up and gave a big improvement over stock and a good fuel mileage increase.

[4wheeldrivefun]

yep, this thing is super slugish (if thats a word) I nearly didnt make it up a few hills today i had to floor it and do 30mph the hole way :-( and transmisson shifted fine. The engine rev's ok in N. Its gota be the cat I cant think of anything else i havent already replaced. I just can't deside if i wanta go with a high flow or a straight pipe. How big of a differance are we talking about high flow vs a open straight pipe power wise.

[Precise1]

Or my other option is to go to a high flow cat. Has anyone done this? Will it throw a check engine light if i do this?

 

Yes, I just had a Magnaflow cat (2" diameter) installed last weekend. It was with headers and a cat back system so I can't comment on what it alone did, but the difference between a high flow cat and a punched cat is not much, and if you want any low end, you probably want the slight restriction of the cat. Ask Andreus009, he cleared out much of his exhaust and is adding stock pieces back to it in hopes of properly tuning it. 3" and straight isn't the best answer unless you are running nascar...

 

B

[JesseLivingston]

Sorry to hear about your issues. Something is definetly not right. If the truck isn't missing, and you don't smell heavy gas on the exhaust then the engine is probably running fine. I'd check brakes for stickyness, e-brake, bearings, hubs. It sounds like something is physically preventing the truck from moving. Drive shaft? After driving the truck for 10 minutes, pull over and check all wheels, shafts for excessive heat.

[andreus009]

I was going to just hollow it out, however dose anyone make a replacement pipe to just reaplce it straight thew? Or my other option is to go to a high flow cat. Has anyone done this? Will it throw a check engine light if i do this?

 

I hollowed out the main cat (the big one) and sleeved it with a piece of exhaust pipe I bought at the local auto parts store. So essentially I have a straight pipe through. A real cheap and relatively easy modification. As a trial, you could just pull out the exhaust up to and including the cat. This would give you idea of how the power would be affected by deleting/punching out the cat, before you actually commit yourself. Obviously it probably will be obnoxiously loud, but at least you have not committed yourself to anything. Actually, now thinking about it you could do it in stages. Pull out the exhaust up to the cat and try it. Then pull out the cat itself and try it. It is possible there is a clog in the muffler or tail pipe section. I had this happen when I punched the cat (before I sleeved it) and didn't get all the pieces out. A piece got stuck in the tail pipe and block flow thus reducing my power.

 

(My mistake in the whole exhaust moding, was hollowing out the pre-cat. You may or may not have on of these. Look at the exhaust shortly after the 02 sensor. If there is a bulge in the exhaust then you have a pre-cat also. Why? Nobody is exactly sure why this was done on same of the later WD21s except for some emission requirement somewhere. Also, I didn't start throwing CEL until I modded the pre-cat)

 

Edited November 11, 2009 by andreus009

[Precise1]

If there is a bulge in the exhaust then you have a pre-cat also. Why? Nobody is exactly sure why this was done on same of the later WD21s except for some emission requirement somewhere.

 

What I learned when I was reading up on what I could use in California (from an independent exhaust site, not pathfinder specific) was that the precats purpose is to heat up quickly from a cold start, reaching the required temperature for the catalytic reastion faster than the full sized cat. They also said something about it helping maintain the exhaust temperature when warm, but I didn't really understand that part.

In effect, it is simply a smog cat for warmup and should not (significantly) effect emmisions when the engine is warm.

 

B

[4wheeldrivefun]

thankfully I don't live in callifornia, emissions must suck. Anyways ya my tailpipe is black on the inside. When I fist start the car apx 2-3 min afterwords the car blows white smoke and than when it worms up it stops. Is this normal?

 

 

What I learned when I was reading up on what I could use in California (from an independent exhaust site, not pathfinder specific) was that the precats purpose is to heat up quickly from a cold start, reaching the required temperature for the catalytic reastion faster than the full sized cat. They also said something about it helping maintain the exhaust temperature when warm, but I didn't really understand that part.

In effect, it is simply a smog cat for warmup and should not (significantly) effect emmisions when the engine is warm.

 

B

[jimmaw]

I hollowed out the main cat (the big one) and sleeved it with a piece of exhaust pipe I bought at the local auto parts store. So essentially I have a straight pipe through. A real cheap and relatively easy modification. As a trial, you could just pull out the exhaust up to and including the cat. This would give you idea of how the power would be affected by deleting/punching out the cat, before you actually commit yourself. Obviously it probably will be obnoxiously loud, but at least you have not committed yourself to anything. Actually, now thinking about it you could do it in stages. Pull out the exhaust up to the cat and try it. Then pull out the cat itself and try it. It is possible there is a clog in the muffler or tail pipe section. I had this happen when I punched the cat (before I sleeved it) and didn't get all the pieces out. A piece got stuck in the tail pipe and block flow thus reducing my power.

 

(My mistake in the whole exhaust moding, was hollowing out the pre-cat. You may or may not have on of these. Look at the exhaust shortly after the 02 sensor. If there is a bulge in the exhaust then you have a pre-cat also. Why? Nobody is exactly sure why this was done on same of the later WD21s except for some emission requirement somewhere. Also, I didn't start throwing CEL until I modded the pre-cat)

 

:my2cents:

 

 

 

 

notice any improvements since you did this?

[Kingman]

The white smoke is just condensation evaporating from inside the exhaust pipe as the engine warms up. It's completely normal.

[andreus009]

notice any improvements since you did this?

 

Quite a bit of improvement when I punched out the main cat (I dunno if it was clogged or just restrictive). Prior to the main cat mod, I had already installed a Borla Catback, but that alone didn't improve performance any noticeable amount. As I said my mistake was punching the pre-cat. I lost a some low end performance when I did that.

[4wheeldrivefun]

I punched out the cat today. Didn't make any differance at all... Anyone have any ideas of what else it could possably be?

[andreus009]

Did you try it without the muffler re-installed? If the issue is in the exhaust, then it could be before or after the cat.

 

Other ideas:

- Bad O2 sensor making it run too lean? I'm no expert on O2 sensors so maybe someone can shed some light if this is possible. I think typically when O2 sensors go bad, the default is to run a little too rich.

 

- Intake air flow restriction. I once had a friend who somehow got a whole bunch of paper towels stuck in his air box. The towels blocked the filter and he lost significant power.

 

- MAF sensor?

 

 

Personally, if I still suspected an exhaust issue I'd temporarily pull out everything up to the cross-over pipe. Cover and tie up the O2 sensor. Test drive. If you don't feel any improvement in this case you can pretty much rule out everything downstream of the cross-over.

 

(Note: If you don't have the pre-cat you could probably stop at the pipe the O2 sensor is screwed into and leave the 02 sensor in place)

[blackpirate]

yep, this thing is super slugish (if thats a word) I nearly didnt make it up a few hills today i had to floor it and do 30mph the hole way :-( and transmisson shifted fine. The engine rev's ok in N. Its gota be the cat I cant think of anything else i havent already replaced. I just can't deside if i wanta go with a high flow or a straight pipe. How big of a differance are we talking about high flow vs a open straight pipe power wise.

 

 

 

Hey I have the same problem exactly. i have a manual 95 xe. I bought it with a seared bold underneath the manifold and managed to get it patched up pretty good it just has a small leak now barely noticeable., But I have to over rev it off the line and the smallest hills its path_etic haha. I thought after i got the exhaust leak fixed id have my power back but not the case. I a mechanic tell me it could be a catalytic converter as well so i am going start from the cat and see if that helps i think. let me know how things pan out