So I have a 97 Maxima(131k miles now, bought at 125k) that i bought around almost 2yrs ago, and I do remember this car having more power(able to rev to 4k RPM) than it is today, and I was curious why my power/ acceleration has gone down in the course of 2yrs and I just realize that...

Maxima's DO NOT like 87 Octane gas which I have used the past 6k miles I have drove in almost 2yrs (3k miles a year) But I drive it 15-30 miles 5 times a week. and heard If you drive with 87 gas, It will drive like crap and have very low power, feeling very heavy accelerating. But it does Idle fine and drive well, but when it comes to that power.. Its just NOT THERE, It wont even Rev past 2k RPM
However I do not hear any weird noises no knocking sounds or whatever.

Stupid of me that I have been using 87 Octane gas and Should of had been using 93 Octane Gas(premium) the whole time... but If I only drove 6k miles/2yrs of 87, I hope that Isn't too late to go back to Premium gas.

So Today I drove alot to get nearly empty tank on my 87, and I filled it up with 93 premium gas, I Did Not however notice any difference Instantly but It did feel like It was trying to Adjust back to what Its used to.. but still had that lack of power trying to accelerate.

So If I keep filling up my Car with 93 Premium gas, over time will the ECU computer or whatever adjust and hope to pick up the power it used to have before? when I go up hill, with 87 Gas Its like I drive like a granny trying to get up there, but eventually go up. but normal driving, It still drives slow with 87 Gas.. I just MISS THE POWER it had. No check engine lights or any lights On dash. All lights work on Ignition mode

 

Your problem is not the 87 octane gasoline. Between my 94, my 97 and 2000 Maximas, I have driven over 250,000 miles on 87 octane. And the performance is excellent.

If your engine can't rev over 2500 rpm, you have a problem. The engine is operating in what we call "limp mode". IF you don't have a check engine light on, the MAF is probably the problem. If the check engine light is on, then do the repairs for the codes you have.

 

That's what I was guessing cause I have no check engine light, It feels like theres not enough Air or fuel going through freely.. something for sure is clogged up. Just not sure what exactly It is.


And also do u think those Fuel cleaning services for $99 are even effective? they say they clean the MAF, Injectors, Throttle body and thats it i believe. I went to valvoline a couple weeks ago and asked them I wanted 2 do the service but they said my car was clean already, and I felt like they were too lazy or refused to do it. even though I know my car doesn't even rev past 2k RPM there is some serious cleaning I need.

And some people say those services do worse than good. Don't know if thats true or not.

 

Bro, did you read DennisMik's post? Stop assuming what the problem is and listen to experience.

Unplug your MAF. If the behavior of your car does not change then replace the MAF as suggested above. Otherwise check for codes and post back the results.

Run the recomended octane as the Maxima has issues with the knock sensor. (Under normal conditions there is no long term damage to be done by running lower octane.)

Those fuel cleaning services do nothing you cannot for $12... There is no magic to it. They just use the same type of cleaners as you can get off the shelf. If you can tie your shoes, you can 'clean your fuel system'.