Recently my car has been suffering with the lack of power. Reading posts, it seemed the consensus was replace the maf with a unit from a 2001 unit. I did this, power came back for a bit...

Lately, the power loss has been getting bad again. I figured, well, I am at 90k, it prob wants new plugs(they are on order). Tonight, I get some codes, and pull them.

P0139
P1147

Consensus is a new o2 sensor is needed?

 

im in the same boat as you....100k miles...jus did plugs..only cleaned maf at one point 10k miles ago..and i just hate how slow my car moves
my guess i need to replace maf and knock sensor, ses light is on. will list codes tomorrow

 

Clogged Pre-cats/Main Cat? I honestly think many cars suffer from restriction in the exhaust when the mileage gets higher....Gut them or try some Cattman stuff

Mine were seriously clogged and really slowed me down in the upper rev range.

 

Honestly I am ready to trade it and get a chevy tahoe.

 

Bad O2's can eff things up including your CATs. As already said, bad CATs kill performance.

 

defitnely your cats

 

Whats a replacement high fkow cat setup thats ready to bolt in cost?

 

If you haven't read through other threads, here's a pro tip: clogged cats will kill the motor. You're lucky that you have warning signs.

 

cats...more than likely the pre cats. Get some headers, and change them sooner than later. what does the rattle sound like?

 

Like a heat shield is loose. It doesn't do it all the time, mainly like if I am in too low of a gear than I should be, then it is noticeable.

I think if anything I will try the o2 first. Is there someone that makes a bolt on aftermarket set? I don't really have the funds or the need for new headers.

 

Good luck on whatever you do its all going to cosy money if you got a 00-01 Max those SSautochrome.com got headers for 250 about that and everything with factory pre cats or some sort are not that cheap!! So Good Luck!~!!

 

I did this write up a while back. It explains my power loss, rattle and solutions. Check and see if its the same rattle.

http://forums.maxima.org/5th-generat...questions.html

 

headers......get rid of yr clogged cats

 

You can look into low mileage used cats from someone who put headers on their car if you want to fix the problem cheap.

 

The exhaust rattle might be a loose heat shield - and the power drop could be a clogged fuel filter?

 

I'm having similar problems with my '01 i30. I replaced the MAF, and I did notice a slight increase in acceleration power, but if I floor it or gradually accelerate up, the engine just hangs at 5k RPM, and I have to lift off the gas a little to get it to shift gears. I had someone check the pressure from the fuel pump and he said he didn't think it was the filter or the pump, and he checked my exhaust and said it didn't look like the cats either. However, when my friend was following me and I gunned it, he said that some nasty smelling black smoke was coming out.