dmk11

WARNING: Long story

Background: Well, I'm a new stick driver. I've been driving my bf's 96 5spd maxima for a week or so when the CEL turned on (code shows left O2 sensor & knock sensor). I reset it and a few days later it turned back on (same codes). Then I found out that my bf has been putting 87 gas ever since he bought the car. I switched to 91 gas and reset the CEL and I've been driving it for over 1000 miles and it hasn't turn back on.

Conclusion: I suck at driving stick and would turn on the CEL if I have 87 gas but it's fine if I have 91 gas.

Question: What could I be possibly doing wrong in shifting that would cause something like this?

Side note: Anyone wants to buy a brand new Bosch O2 sensor I recently got since I won't need it anymore?

clee130

Would shifting wrong cause the CEL light to turn on? Doubtful.

There could be a whole bunch of reasons for the CEL turning on. Putting in 87 gas might be one of them, maybe. But I used to put in 87 in my Max all the time and I never got the CEL.

I switch over to 91 and still didn't get the CEL.

If the CEL doesn't come on again, you should be in the clear. But hang onto the O2 sensor. You never know when it might come in handy. You paid for it, might as well hang onto it.

ATt

Whenever the computer is reset there will be a lose in gas mileage. For about a quarter tank the car runs with a rich gas mixture, I'm not sure as to why it does this though. I'm telling you this just fyi incase you did not know this already.

for some productive stick driving tips check out this tread http://forums.maxima.org/showthread....5&pagenumber=1


SHIFT_alex

dmk11

The reason why I concluded my shifting caused it is because my bf drove the car for 6 yrs w/ 87 with no CEL then when I drove it for a week the CEL turned on. So it must be the way I'm driving. It's a combination of the 87 gas and my driving that cause the CEL. Not either reason independently.

Jason R

iTrader: (39)

O2 sensors and knock sensors do tend to go bad, ya know...

clee130

Well, if the CEL doesn't come back on, there should be no problem.

dmk11

Thanks for the link. I'm downloading those videos now.

But obviously I'm doing something slightly wrong if I turn on the CEL w/ 87. I just want to tune my technique so I can use 87 again on the car..

ATt

shifting technique and the grade gas you use effect 2 different things. Bad shifting wears out the clutch and gear synchros. Low grade gas is bad for fuel mixture.

ATt

how m/t works
http://www.howstuffworks.com/transmission.htm

how gaseline works
http://www.howstuffworks.com/gasoline.htm

read this too
how car engines work
http://www.howstuffworks.com/engine.htm

happyricefob

iTrader: (7)

my max runs fine on 87 unleaded... but since u tried both 87 and 91 and the CEL still on, so i don't think it's the gasoline problem...

ThurzNite

iTrader: (13)

When the light comes on, take it to Kragen and get the code (don't listen to their explaination...it's usually generic). Then post on the board what the 4digit code is and we'll help you from there.
BTW, once the light comes on, it takes about 27 warmups (from cold to normal temp) to calibrate the ecu...so that's roughly 2 weeks of driving.
Jae

iansw

iTrader: (7)

It specifically says in the Nissan Maxima's Owners manual that the car MUST use 91 or better octane fuel.

While I don't at all see how shifting could affect this along with 87 fuel, I do see how years of driving it on 87 can cause those codes.

So stick with 91 or better, and make sure you don't skimp at all - ever.

I bet your bf was using AM/PM (Arco) or 7-11 (Citgo) gas.

BAD stuff.

IanS

spiff56747

iTrader: (-1)

why would you go to kragen to get the code... is it free?

njmaxseltd

iTrader: (19)

Hang onto that O2 sensor. You can bet your last dollar that CEL will return with the same O2 code. They go bad ya know. Your is probably just on the border line. Give it some time.

Jamsan

iTrader: (2)

those videos are great....maybe ill learn how to drive 5spd after all

now only if i could find a friend with a 5spd that would let me learn on their car....anyone in the CT area wanna let me borrow their 5spd max for a few hours

blizz20oma

iTrader: (1)

I don't think it says must in big bold letters. Or if it does, it appends on "to achieve maximum performance" on the end.

If your BF is a big fan of 87, and has used it for a while...the knock sensor likely had to work harder over time, which may shorten its life. Of course, KSs are a little tricky in the sense that it's not a clear cutoff when it goes from good to bad. I'd keep the O2 sensor, more than likely it may be on its way out. If the CEL doesn't come on, I'd still check codes in a couple weeks to see if hte KS is still reported as acting up (CEL may not come on for this alone).

You could test the KS with a multimeter. I'm willing to bet if your bf has owned the car for a long while and always used 87 gas, it may need to be replaced. Do me a favor and smack him for putting that gas in a 5-speed max.

I don't think your shifting has anything to do with it.