Well, I dont often create threads on here so I though I'd give it a shot and share my pain as well as gained knowledge from these past couple of days.

Bought car in June 2008 without a Cat/o2 so I've always had check engine light on. This week however after all this knock sensor talk, I noticed my car was quite on the laggy side and I've known for some time I've been needing a fuel pressure regulator since the lil pipe for the vac hose was broken. Went to Advance Auto and checked which codes I had, I had a crap load, 5 of them in this order
P0150
P0325
P0135
P0155
and P1400 (for the past year)

Having all these codes and getting real poor MPG really motivated me to get on it, I'm getting 18mpg which isnt too great at all. Installed ebay KS, JY fuel pressure regulator that wasnt broken (they're not known to go bad from what I've seen), also did a bit of research here and found out P1400 is the EGRC which is incredibly easy to replace. During the process of all this I pulled the TB to gain more access to the FPR and well I had an OEM TB gasket laying around for 2 months so why not, alright during this process I sprayed carb cleaner on the inside and outside of the TB to clean it up a bit while there. Went and got my CEL cleared to make sure only O2 sensor codes came back and not KS or p1400.

Fast forward to the test drive, my car still felt laggy, I had a feeling the TPS got damaged with the carb cleaner sprayed on the inner part so I went to check the resistance and wasnt getting any, plan was to replace it with a known working one so I plug the old one back in and it worked fine but with a lag still. Today as I'm driving when I came to a stop and the idle dropped to 1k it was fine but then it kept getting lower and lower til about 400 rpms and then when I gave it a bit of gas to bring it up, it just stalled. Kept doing it, went Advance and got another reading, this time only two codes:
P0120 TPS circuit malfunction
and P0150 O2 band 2 sensor 1 circuit malfunction

Apparently I didnt secure the TPS plug all the way and it came loose, this time I pressed it in til' it clicked, the problems went away but I still had the lag. Went to Advance AGAIN and got everything cleared and hope that one one code remains. As for the lag, I went home and checked resistance on my 3 front injectors, the middle one is at 15.4 ohms, FSM states they should be between 10-14ohms, tomorrow I'm gonna have to hit up the JY with my multimeter and grab a few 10-14 ohmed injectors and pray this is the cause for my poor performance. It stumbles very subtly which lead me to believe it was the coils but I know the injector is bad so until tomorrow I wont know.


Sorry for the long read but what do you guys think? being 1 ohm over the spec would make that much of a difference?

 

Took my happy *** to the junk yard this morning with my craftsman locking pliers aka vicegrips, a phillips screw driver, and my multimeter. Found a 96 Infiniti I30 with all 3 front injectors still untouched, all ohmed out at 11.4 so I went ahead and loosened the screws on all 3 injectors with the vicegrips and used the screw driver to finish unscrewing them.

Once all three were out, I checked for obvious damage and they all appeared to have been replaced before and had nice new looking pintle caps and all.. they also had tiny Nissan burgers on em and part numbers which leads me to believe that I got lucky and scored recently replaced OEM injectors...

I already replaced the injector, drove to Advance to make sure TPS code didn't return, sure didn't..all I have to worry about it the P0150 and thats because I dont have a cat/O2 sensor. Max drives fine but wont find out how much better until I drive it to school later today.

 

How do you test a fuel injector with an ohm meter?

 

This is only to test the electrical condition of the injector and in no way will it tell you if its clogged or not but chances are that if the electrical part works, then the injector should be fine.

Set your multimeter to Ohms most likely 200 should be the number you set it to.
Take a multimeter, and touch each pin in the injector with the black and red prongs. Your resistance should be 10-14 ohms, if its 14 +.1 or more its no good and if its 10 -.1 then its no good as well.

 

How was your fpr and injector removal/install ?
Piece of cake or pia ??
Any tips?

 

Pull the 15A fuel pump fuse inside the max and crank the car a few times to release fuel pressure..

Front injectors are cake for me, just use vicegrips to loosen the screws so you dont strip them with the screw driver. Once they're loose you can use the screw driver. Use the vice grip to gently twist them left to right as you pull on them.

As for the FPR, move the air intake and TB out the way and use the same method with vicegrips to loosen the screw first. its pretty much straightforward. Get a fuel clamp just in case the one there is old and crappy looking you can just replace it with a new one.l