[2006x]

I am wondering if anybody might have suggestions about what to look at as a possible cause of the following:

Basically, when I accelerate whether light or hard, the vehicle reacts poorly (as if someone is applying the brakes). I brought it into the dealership and they checked it out visually and put the scan tool on it and couldn't find any obvious problems. The tech agreed that something was amiss but because the scan tool didn't pick up anything, he's giving my 2006 Xterra a clean bill of health

While it feels like the front brakes are dragging excessively, the techs confirmed that is not the case. There are not any "signs" of dragging present on the rotors either. The calipers don't even get hot.

What might I look to next that might cause my ride to seemingly fall flat on its face when pressing on the accelerator.

Thank you in advance...

 

[xterrock]

That sucks ... dealer mechanic acknowledges that something is not right
but since 'technically' nothing is wrong, nothing will be done. You shouldn't
be the one trying to figure out what's wrong. You should take this up with the
supervisor or even higher up. I had a pretty favorable experience dealing
with Nissan corporate about a repair under warranty.

 

[Terdar]

when was the last time you checked your air filter?

 

[syndicate]

E-brake? lol

 

[RogueClimber]

Is it the engine not performing or is it the engine fighting some sort of anchor?

 

[mike100]

One time these dudes at works stuffed a potato in my tailpipe 9and it froze solid... had about 4 hp.

when catalysts get clogged, you can't make any power past a certain load point on the accelerator pedal.

 

[2006x]

While I've only got 8000 miles on my X, the air filter is particularily black in some areas. But I don't think enough to impede air flow substantially. Maybe I'll change it just in case.

The tech did say that it's possible that the catalytic converters may be having issues but he suggested that they would have been able to pull a code for that (I think E420 is what he said).

Even the Service Manager/Director spoke to me. He was nice and completely understood my frustration. I told him that I'll probably be in again cuz it sucks to have a new vehicle that drives like SH*T

 

[lostboy]

no answers for you but make sure to keep us updated on what you find out if you ever do.

 

[2006x]

I'm really stuck on the fact that the front brakes were clamped down so hard when I lifted my rig's front end off the ground and tried to rotate the wheels. I figure they should spin as freely as the rears which spin smoothly without any excess friction.

I know that supposedly the rotors would have some telltale signs of dragging and that no sensors picked up any oddities, but is it not possible that something that is NOT monitored could be out of adjustment? Like the pushrod that is part of the master cylinder/brake booster? Or possibly something that is causing the VDC to activate more aggressively than it should.

However, I still need to look into the possibly impeded Catalytic converters or the air filter maybe being just dirty enough.

 

[mike100]

you can tap a small hole in the exhaust upstream of the cats and measure the backpressure under idle (not underway) conditions....more than 1 psi or so and the cats are plugged. also there are specs for under a load as well.

compare it with a good car...possibly you only have one bad cat on one side of the engine.

 

[2006x]

thanks mike100, I'll keep that in mind

 

[mike100]

I forgot to say that you rev it in neutral, not measure at idle... but anyways if you get 2+ psi backpressure in neutral just sitting there, your exhuast is plugged. 80's Volkswagons' used to have a test port just ahead of the cat... I wish all makes had this.

 

[2006x]

mike100,

I think I may see if I can find some catalytic converters from a junkyard 05 or 06 Xterra. I priced them online and they're $500-600 each.

Would a clogged or partially clogged cat result in a general sluggishness or heavy feel to the vehicle upon trying to accelerate? I've noticed that the increase in RPM's when pressing on the accelerator in DRIVE doesn't seem to correlate with the MPH as well as I would imagine it would. The engine always seems to be trying to overcome some hinderance. I've even heard pinging when attempting to accelerate at highway speeds.

As always, thoughts or input is greatly appreciated...

Terry

 

[Muzikman]

If the RPM's are up, it almost sounds like a driveline problem.

Oddly, mine was doing a similar thing on Sunday, but while in 4Lo. I know 4Lo cuts the power, but I have had the thing in 4Lo enough times to know when something didn't seem right.

I took it out of 4Lo and then back in and everything seemed to be back to nornal.

 

[Terdar]

Disconnect the battery for a while ( I think 15 minutes) and make the CPU relearn all the settings. It should fall back on safe/default settings for a bit and then relearn the fule:air ratio and such. I doubt it's the problem, but what the heck.

Check the MAF and see if it's somehow dirty.

Pinging usually means the timing is off or running lean (correct me if I am wrong).

 

[robnfl]

According to the owner's manual, some pinging is normal...

However, now and then you may notice
light spark knock for a short time while
accelerating or driving up hills. This is not a
cause for concern, because you get the
greatest fuel benefit when there is light
spark knock for a short time under heavy
engine load.

My X seems to be a little slugish at lower rpm's, less than 3K, but I attribute that to the relatively high torque/HP curve, a heavy vehicle and the electronic throttle.

Rob

 

[XVTer]

If the RPM's are up, it almost sounds like a driveline problem.

Oddly, mine was doing a similar thing on Sunday, but while in 4Lo. I know 4Lo cuts the power, but I have had the thing in 4Lo enough times to know when something didn't seem right.

I took it out of 4Lo and then back in and everything seemed to be back to nornal.

I had the same issue. I had used 4WD earlier in the day and shut the X off while it was still engaged. Later, after going back to 2HI, it felt like something was dragging. Switching back and forth from 4WD a couple times solved that problem.
Hope its that simple.

 

[jimrhit]

While I've only got 8000 miles on my X, the air filter is particularily black in some areas. But I don't think enough to impede air flow substantially. Maybe I'll change it just in case.

The tech did say that it's possible that the catalytic converters may be having issues but he suggested that they would have been able to pull a code for that (I think E420 is what he said).

Even the Service Manager/Director spoke to me. He was nice and completely understood my frustration. I told him that I'll probably be in again cuz it sucks to have a new vehicle that drives like SH*T

I hope you don't have to go through what I did.

My truck went through 2 catalytic converters ... stranding me on the I5 outside of Camp Pendleton here (15minutes each way to civilization) and then again in the middle of traffic on the 101 freeway in downtown LA. I had the exact same issues as you ... the car was just a bear to get moving ... and then it would just DIE at 70mph while cruising.

My car was in the shop for 3 weeks and then 2 weeks for this .. and I am one more failure away from a lemon'd X. That said ... after the last fix ... I have a great truck ... but it wasn't without trouble. Get the cats checked out ASAP .. I don't want you to be stranded like I was (luckily winter here is only 60degrees at the coldest, if I were in CO or something, I could have been in trouble).

 

[Wheelhorse]

While I've only got 8000 miles on my X, the air filter is particularily black in some areas. But I don't think enough to impede air flow substantially. Maybe I'll change it just in case.

The tech did say that it's possible that the catalytic converters may be having issues but he suggested that they would have been able to pull a code for that (I think E420 is what he said).

Even the Service Manager/Director spoke to me. He was nice and completely understood my frustration. I told him that I'll probably be in again cuz it sucks to have a new vehicle that drives like SH*T

I hope you don't have to go through what I did.

My truck went through 2 catalytic converters ... stranding me on the I5 outside of Camp Pendleton here (15minutes each way to civilization) and then again in the middle of traffic on the 101 freeway in downtown LA. I had the exact same issues as you ... the car was just a bear to get moving ... and then it would just DIE at 70mph while cruising.

My car was in the shop for 3 weeks and then 2 weeks for this .. and I am one more failure away from a lemon'd X. That said ... after the last fix ... I have a great truck ... but it wasn't without trouble. Get the cats checked out ASAP .. I don't want you to be stranded like I was (luckily winter here is only 60degrees at the coldest, if I were in CO or something, I could have been in trouble).

What year rig and how many miles on it?

Do you know if it was the pre or post cats? My guess would be the pre-cat (first set)

 

[Wheelhorse]

I am wondering if anybody might have suggestions about what to look at as a possible cause of the following:

Basically, when I accelerate whether light or hard, the vehicle reacts poorly (as if someone is applying the brakes). I brought it into the dealership and they checked it out visually and put the scan tool on it and couldn't find any obvious problems. The tech agreed that something was amiss but because the scan tool didn't pick up anything, he's giving my 2006 Xterra a clean bill of health

While it feels like the front brakes are dragging excessively, the techs confirmed that is not the case. There are not any "signs" of dragging present on the rotors either. The calipers don't even get hot.

What might I look to next that might cause my ride to seemingly fall flat on its face when pressing on the accelerator.

Thank you in advance...

You can place a vacuum gauge on the engine and watch the vacuum decrease as you travel down the road.

i.e. Cruise the highway you should be 15-22 depending on throttle, but if you are approaching a hill and you throttle up a tad and your vacuum climbs down to zero without going WOT and maintaining a constant percentage of the TPS, then you have a clog.

May also be comfirmed as suggested with poking a hole upstream, but if it is the primary cat, it is not the easiest to check for back pressure with forementioned and may piss off Nissan.