Nissan cat failure blows the engine

[Nick Warner]

The Xterra and Pathfinder use a baby catalyst that bolts right onto the end of the manifold. They did this to get it up to temp faster for better emissions. If you have one of these come in that has been missing or rough running, try to sell a cat inspection. Pull it down and get a good look in it. What has been happening is that when the cat breaks down, pieces of the broken substrate are being sucked into the cylinders during valve overlap. Sands the rings right out of them and fries the motor.

Not sure what the labor time is to pull the cats off for a peek in them, but may be able to pull the o2 sensor out and use a borescope to have a look at it. At least your customer will be warned, and if they decline the cat inspection make damn sure you document that on the RO. Last thing you need is for them to come back three weeks after you fix a misfire to have a blown motor, and I guarantee they’ll be trying to blame you for the engine since you were the last one who worked on it.

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[Gary]

Amazing… sounds like the same scenario from TSB I read about certain newer GM models. What these engineers do to meet emissions requirements *facepalm*. Nissan quality seems to have dropped off and the Xterra and Pathfinder seem to have gotten the brunt of it with leaky radiators that destroy transmissions and whatnot(another common failure typically 2005-2007 models)

[dan]

wow… genius engineering, i have never liked Nissan.

[Kevin Gallich]

Nickwarner what year nissans? I have a dreaded 2007 Pathfinder that is missing and a rough idle and it is driving me nuts. It also came with the bad radiator and a bad timing belt. I had a 04 Quest that I thought was the biggest piece of crap on the road but this Pathfinder is gaining ground quickly.

[eddie]

ohhh yeah think its called pre-cat failure ,something about a butterfly screw coming loose and getting into the engine , there’s lots of info on B15U.com or other nissan sentra forums .

[Author]

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