[Martize_smith]

Hello all,
I have a 2006 Nissan Xterra 2wd that’s having…a lot of problems right now. My biggest? There’s not much acceleration happening - especially uphill. I’ll top out at about 30 mph on a straight road, but a bit of a steep hill, I’ll put pedal to the medal and won’t get above a good 15 mph. The car idles high - so I thought it was a vacuum leak, apparently not. Multiple random misfires. I changed both spark plugs and ignition coils - but when I was heading back to college from home, more of the same. Took it to a mechanic last week, and got a call back today saying that even he can’t figure it out. Please tell me what I’m missing - I need this car.

 

[outback97]

Step 0) Scan for codes
Step 1) Post codes here

 

[OklaYeti]

Plugged catalytic converters can cause severe lack of acceleration.

 

[mojavedesertman]

Sounds like how mine acted after the primary cats crumbled internally do yourself a huge favor and stop driving it till you get it fixed otherwise you may end up needing a new engine or a rebuild.

 

[LNXPenguin]

Have you checked the coolant/transmission fluid? This sounds like it could be something in the transmission, hopefully not the dreaded SMOD. Look for any P17xx codes

 

[Xtre]

Hope it's not the oil pump, Might do a compression check on the easy to get to cylinders. Usually with clogged Cat's it will sound choked and struggle to rev in my experience agree to get codes from autozone or oreilly both will scan codes for free

 

[Lowcountry idn]

Plugged catalytic converters can cause severe lack of acceleration.

Yep, this sounds exactly like a plugged cat. Multiple random misfires is the most common code - P0300, along with maybe P0420 / P0430.

 

[Xtre]

Could also be that it's in safe mode.

 

[WhtShadow]

Plugged catalytic converters can cause severe lack of acceleration.

I had that problem on my S-10 Blazer. Took forever to diagnose. New Cat fixed it.

 

[Xtre]

I had that problem on my S-10 Blazer. Took forever to diagnose. New Cat fixed it.

It idled high with a plugged cat?

 

[Just a Hunter]

I suspect you don't have one single problem, but rather a couple of issues.
For starters, your high idle is probably a vacume leak or a bad O2 sensor, where as your loss of power could be a bad cat.

Helpful videos.

 

[WhtShadow]

It idled high with a plugged cat?

No load, it would rev pretty well. With a load, it wouldn't get over about 2,500 in the lower gears (I think - that was a long time ago).

I would try unbolting the CATs to bypass - yes, it will be loud - but it will demonstrate.

 

[Xtre]

No load, it would rev pretty well. With a load, it wouldn't get over about 2,500 in the lower gears (I think - that was a long time ago).

I would try unbolting the CATs to bypass - yes, it will be loud - but it will demonstrate.

Its not going to rev well with a plugged cat, none the less barely idle.

 

[WhtShadow]

Its not going to rev well with a plugged cat, none the less barely idle.

Apparently mine wasn't fully plugged - it let some through. I would think that these would be the same. Also, with two CATs, they don't have to both fail.

 

[jefferydlong]

Hello all,
I have a 2006 Nissan Xterra 2wd that’s having…a lot of problems right now. My biggest? There’s not much acceleration happening - especially uphill. I’ll top out at about 30 mph on a straight road, but a bit of a steep hill, I’ll put pedal to the medal and won’t get above a good 15 mph. The car idles high - so I thought it was a vacuum leak, apparently not. Multiple random misfires. I changed both spark plugs and ignition coils - but when I was heading back to college from home, more of the same. Took it to a mechanic last week, and got a call back today saying that even he can’t figure it out. Please tell me what I’m missing - I need this car.

Did you ever resolve this issue? I'm having the same problem on my '06 Frontier. I previously replaced a bad coil pack and it was fine for a couple of weeks. The this happened. I replaced all the coil packs and plugs and no change. Any help would be appreciated.