So I recently sold my 1 of my 4th gens which just had an intake and catback, performance wise. But we had it up to 137mph with little effort, It was a 5spd with 167k miles.

But I got a 2002 maxima with 140k 6spd, And we could BARELY make it to 115... Which makes me think something is wrong.

It does need two 02 sensors but they're bank 1/2 sensor 2's, which from my understanding didn't really do much. And it has something wrong with the EVAP system, that's because of the gas cap tho.

What do you guys think it could be? It's completely stock except for an intake. (for now)

 

You should be able to go a lot faster. Is the car an SE? if so, you shouldn't have a governor to limit your speed.

It's been a long time since my car was stock so I don't remember exact speeds but it never topped out that slow.

With my current mods I can easily top 150 MPH.

 

Yeah that's weird! I would try replacing the plugs and possibly doing the seafoam trick. I easily break 115mph in 4thgear. Could I'm sure it's something simple!

 

I'm trying to find out why my 6 speed is no faster to 110mph than my auto and my auto has messed up cats. My 6 speed should be quicker

 

It doesn't top out at 115, just takes FOREVER.

And I bought the best plugs I could about a week ago, Coils looked real good too.

You think I should seafoam it?

 

I wouldn't worry about Seafoam right now. You've got something more than just a little carbon buildup. That car should scream right past 110mph and walk a 4th gen.

This might sound crazy but check to see if your brake lights are staying on. The stop for my brake light switch fell out a few months ago causing the brake lights to stay on. I didn't notice the lights but there was a loss of power. For safety reasons, the computer cuts the throttle when the brake lights come on. The car drove fine but felt like a weak four cylinder car. No other symptoms or CEL. I didn't figure it out till I closed the garage door and saw the lights on.

You might try cleaning the MAF and/or swapping one in from another car to test it. Especially if the car came to you with a modified intake. It's possible to have MAF problems that don't throw a CEL.

Also, make sure you figure out for sure what the O2 sensor code means. If it's one of the upstream sensors that might be it. The downstream sensors just tattle on you if the precats go bad.

 

Your exhaust must be clogged somehow.

 

You mean the brake lights stay on even after the keys out? Because that don't happen, just the auto lights. I did however change out my taillights and now there's a red light on in my cluster, not sure what it is, it's on the left of the cluster.

The intake is like a ripoff of an injen, Is there any special way to clean a MAF?

Both my o2 codes are bank 1 and 2 sensor 2's, which are downstream. (i think)

I do have a Cat-back on the way, along with a test pipe. If that'll help anyway i don't know.

 

So I cleaned out my MAF and got better thorttle response but not better top end at all.

I did notice however that my o2 sensor next to the radiator wiggles around and is pretty rusty, They suppose to wiggle around? I don't have a code for the upstream ones however.

 

let me know if you fix your issue, have a similar problem but mine is automatic, regular driving is fine, just getting on the throttle seems like something is holding it back from full power but no check engine light though.

 

maybe the butterfly valve in the intake manifold isn't opening up?

 

Wow.....with Torque Pro, a phone app, and a 20 dollar Bluetooth OBDII device, you guys could see everything your car is doing almost. Even datalog it, email it to yourself, go home and sit in your recliner, and look it over.


On this forum there is a schematic for making your own O2 simulators, ive used it, works fine.

 

how does this work because im interested? I dont like to throw parts at cars if its not gonna fix the issue.

 

https://maxima.org/forums/5th-genera...oid-phone.html

get a dyno, tells you what HP you're putting down at what speed.

http://i4.photobucket.com/albums/y12...ps8493e182.jpg

 

kool man