# 2001 Nissan Sentra Sluggish Startup - Loss of Power - Any Ideas?



## utseay (Mar 29, 2011)

Car: *2001 Nissan Sentra 1.8L*
Recent Attempts to Fix: Changed air / oil filter & spark plugs. Cleansed fuel system (throttle body cleaner and fuel system flush).

I have two issues that'd I'd like your opinion on:

1) *Sluggish Startup / Power Loss / Fuel Economy Loss*
Description: When I start the car, it acts like it wants to die, then every time I go in reverse (i.e. backing out of a parking spot), it dies. Sometimes twice. It rarely dies when I start out going forward, but has happened a few times. Once I start going, its fine. When sitting at red lights the idle is a little rough. I've also noticed its not got as much power when accelerating and I've dropped from about 29 mpg to about 24 mpg.

2) * Exhaust Rattle*
Description: When accelerating I hear a rattle, similar to a bunch of bb's in a can. This got increasingly worse when I ran the gas very low one day.


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## Tlgifford (Jul 27, 2011)

I would say it is youre mass air flow sensor. Mine was doing the same thing and it cost about $400 to replace


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## SPEEDO (Jun 9, 2003)

could be a few things cam/crank sensor, 02 sensors, bad cat etc... but lets start at.. any codes?


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## smj999smj (Jan 1, 2006)

Last, but not least, check for bad head gasket.


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## jaysonbarn (Jan 4, 2011)

*Re:*

Did you recognize the exact problem. Want to know the exact issue and the methods to solve it.
Thanks.


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## rogoman (Dec 16, 2004)

- Check the intake system for a possible major vacuum leak. To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source. With the motor fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be around 21 InHg.

If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.

- The CAT may be plugged up. The easiest test for converter plugging is done with a vacuum gauge. Connect the gauge to a source of intake vacuum on the intake manifold. Note the reading at idle, then raise and hold engine speed at 2,500. The needle will drop when you first open the throttle, but should then rise and stabilize. If the vacuum reading starts to drop, pressure may be backing up in the exhaust system.


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