No power when given gas

A few months ago, my '00 Sentra developed a rough idle but I ignored it because it wasn’t too bad, until recently at least. It had been getting progressively worse so I went out and bought some CRC MAF cleaner, which solved the rough idle altogether for about a day. After doing some errands, I started the car but it was now stuck in limp home mode, not matter how much gas I gave it, she wouldn’t top 20 MPH and 2.5k revs. I bought a new MAF, and that made the problem worse: in any drive gears or reverse, when given any gas, the engine would stall and die but when in neutral, I can rev it as high as I want to. I reset the computer and cleaned the new sensor to no avail. After re-installing the old sensor (which was visibly broken, it was missing an entire wire assembly), it will run poorly but will now drive with some quirks, and I don’t trust it further than around the block.

My question is: with the new sensor, do I need an ECU reprogram, did I receive a bad sensor, or is there a compound problem? (I’ve heard with similar issues: bad alternator, bad TPS, bad IAC module, dirty IAC or TPS, clogged fuel filter, bad fuel pump, dirty air filter, among others.)


Yes, do the basics you mentioned

Clean the throttle body and IAC first

I wish someone had a real answer for this one. I am having the same problem with my Nissan Sentra. Help please. I have replaced all the oxygen sensors, the catalytic converter and the MAF and still the same problem as described above.

I had initially purchased an aftermarket MAF, hoping to save a little $$$. I ended up going to Autozone and buying a remanufactured OEM sensor…after installing the $300 sensor, it ran better than when we purchased it.

In your case, I would double check to make sure you have a quality sensor, or sensors since you replaced them all. What I came to learn is the engine is mapped very specifically and poor quality parts won’t allow it to run well.

Good post @johnbkremer … reminds us all that sometimes a penny saved isn’t a penny earned. It is a dollar and a half lost instead.

Many aftermarket parts work fine. But there are some parts, mostly those affecting drivability – to me at least – that don’t make sense to try to pinch pennies by buying aftermarket versions: MAP, MAF, O2 sensors, I think it is dollars and time saved to purchase them new, from the dealer if possible, and if that’s not possible, as OEM rebuilds.

I bought new parts from, not really thinking about that because they said they were new. Were these maybe poor quality parts? I really don’t want to scrap my car or waste money on parts that won’t fix the problem. Maybe I will try buying a remanufactured OEM sensor too. I don’t know what to do.

Or have a qualified shop look at it?

It has been at my mechanic’s for a month and he can’t seem to figure out the problem. He has checked everything he can think of. I am 200 miles from a Nissan Dealer or I would take it to them. Right now you can’t drive it and it is too much money to have it towed. This was my last resort hoping someone would have an answer to the problem.