Thread: What is this?

The car, '99 Sentra SE-L

It says: "evap service port, 1 psi maximum regulated pressure only"

What is this for? Are you supposed to service this often? If yes, who can perform this or how is done? I got this car almost a year ago. Is been a good car, but it has a bad hesitation from 2000-3000rpms. I have done almost everything, complete tune up, check timing, FPR. Next on the list is to check the fuel pressure. But I'm thinking it could be the maf. No ck engine lights. Any ideas?

Only 81k miles.

that's for hooking a smoke machineup, to check for evap gasoline leaks.....

what kind of parts did you use in your tuneup?

New sparkplugs and wires, fuel filter, air filter, new pcv, ect. It not throwing any codes, no CEL. No air leaks either. I disconnected the MAF, and improved a little. Which make me think it could be the MAF.

I was having pretty bad part-throttle hesitation. I can't tell if that's what you're having or not, but here's the thread that describes my problem and the hose that I found that was the source of the problem:
http://www.sr20-forum.com/general-sr20/23550-part-throttle-hesitation.html

On that thread, Andreas Miko mentioned that a bad O2 Sensor can cause this. The question is, can this car have a bad O2 sensor and don't get a CEL? I know this is possible on most '91-'93 SR's, but I dont know on '95-'99. Also, I'm sure the car does not have any air leaks.

I haven't changed my O2 sensors because the car is not throwing any codes.

unplug it and find out

Done a simple MAF clean? I highly recommend CRC's MAF Sensor cleaner. You might also want to reground the wiring if you haven't already. Wouldn't want to spend money you don't have to. My guess is dirty MAF/TB, O2 sensor, or both.

MAF Sensor Grounding

Not exactly your issue, but maybe something here will fix it?
http://www.sr20-forum.com/general-maintenance/38-how-bad-idle-troubleshooting.html

I cleaned the MAF already, it did not work. I need to check the O2 Sensors.

stock ecu?

Yes! The whole car is completely stock