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My '01 has 125,000 miles and has never had any major service. In the last few weeks, it has displayed a (primarily low end,) power loss intermittently, which has become more frequent over time. When the power is down, it feels like I'm missing about half of the horsepower. It seems like there are about 3 different "levels" of power -- 200hp, 300hp, and full power. I get 200hp about 15% of the time, 300hp about 60% and full power about 25%. And it can go from one to the other multiple times during any given trip. Earlier today I was driving home (about a 15 minute trip,) and I was in the 300 range then suddenly I hit the gas to pass someone and all 400 were there waiting for me.

The fact that this is intermittent suggests to me that it's a sensor somewhere. I do have the check engine light on but I don't have a Peake (I know, 125,000 miles and no Peake but I'll fix that soon,) so I don't know what code it's throwing. Just wanted to see if anyone here had any ideas of what the cause could possibly be.

Thanks
Todd
 

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My '01 has 125,000 miles and has never had any major service. In the last few weeks, it has displayed a (primarily low end,) power loss intermittently, which has become more frequent over time. When the power is down, it feels like I'm missing about half of the horsepower. It seems like there are about 3 different "levels" of power -- 200hp, 300hp, and full power. I get 200hp about 15% of the time, 300hp about 60% and full power about 25%. And it can go from one to the other multiple times during any given trip. Earlier today I was driving home (about a 15 minute trip,) and I was in the 300 range then suddenly I hit the gas to pass someone and all 400 were there waiting for me.

The fact that this is intermittent suggests to me that it's a sensor somewhere. I do have the check engine light on but I don't have a Peake (I know, 125,000 miles and no Peake but I'll fix that soon,) so I don't know what code it's throwing. Just wanted to see if anyone here had any ideas of what the cause could possibly be.

Thanks
Todd
I would think MAFs or possibly a CPS. When the exhaust CPS starts to go bad (before it throws a code), the exhaust sounds kind of flat, it has been described as "blatty".

As to MAFs, get some MAF cleaner (not carb cleaner!). CRC is one brand. If you get some improvement, replace MAFs. Cleaning is usually temporary. Conventional wisdom is MAF's are a wear item (60k miles).

Regards,
Jerry
 

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Also if you are running aftermarket filters and oil them, be careful not to overcoat them as these can get on the MAF and ruin them prematurely.
 

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Ok this afternoon I disconnected both MAFs and that made the problem MUCH worse. Just off idle it was sputtering and almost stalling. I reconnected them and everything was back to normal. Can I then assume that the MAFs aren't the problem?
Yes, that makes sense to me. The intermittent power loss screams CPS's to me. Their internal Hall-effect electronics seem to get glitchy as they get old, probably exacerbated by underhood temperature.
 

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Ok potential dumb question coming -- CPS = cam position sensor correct?
Correct. If they've never been done, you really should just do all 4 regardless of what codes you have.

That said, before anyone can guess more we really need to see what those codes are.
 

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If unplugging the MAFs made a big difference..... that should not make a big difference. Likely you have fuel trims way out of whack from lying Mafs or an air leak and when you unplug them a new fuel curve is set. I would suggest you unplug them again and drive the car more. Likely the car will smooth out. You could do the MAF test just search those words if you have no idea what I am talking about.

I vote for replacing the 4 CPS not for any other reason than it is a good idea and resolves so many problems. Not because of these problems just because... Although it may help,you must have more than one thing going on.
 
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