sthompson418

I am going down this road now, my wife took our 1999 maxima to have the codes read at AutoZone, and it came back with misfire #3, EGR valve and Knock sensor. I changed the plugs when we noticed the first sign of hesitation and no change, I replaced the coil pack for #5 mistakenly after getting the wrong cylinder location info on another site. But I did take the coil that I took out of #5 and put it in #3, no change. The car will not stay running when it is cold unless you give it some throttle and then it will run on ok. The plugs didn't seem like there were any one blacker than the other, just the electrode worn down from lack of maint. (we just got this car) My question is, does this point to a bad injector? Does this cause the low fuel pressure at cold start? Does the EGR valve have anything to do with this? Please help

ChrisMan287

iTrader: (34)

Sounds like an injector issue since new plugs and coil didn't solve the issue. While the injector or o-ring is being replaced you might as well change the KS and clean the EGR.

The KS or EGR will not cause your issue.

njmaxseltd

iTrader: (19)

Seems like you've ruled out the coil. The injector could be bad, you can do a simple test to see if it's firing. Put a screwdriver on it and put the other end to your ear. You will hear it "click" as it fires. If you don't hear anything, it's dead.

The EGR systems on our cars are known to get blocked up. What was the code pulled?

The knock sensor code sometimes comes up as a ghost code when other engine codes are present. Fix the misfire and get the EGR system running correctly, then check for the knock sensor code. If it comes back, replace that sensor too.

sthompson418

Thanks guys, I'll do that check on the injector and get the other suggestions done asap. I will let u know how it turns out

sthompson418

BTW,.....are the injectors hard to change? any special tools or things to watch for? I am an Agriculture diesel mechanic....just curious

Quickywd01

iTrader: (16)

No special tool required.

ShocknAwe

iTrader: (3)

They are fairly easy to remove just a little stuck sometimes. Elbow grease is the only special tool required

sthompson418

ok thanks

qqiq

recently I also replaced my #3 injector because of P0303 Code. It is really a pain to take the UIM off as described on another thread. One of the two bolts on the back of the UIM (actually only one lest, the former owner may lost one) is very hard to reach. It takes me one hour to take it out and one hour to put it back. My 12mm socket and wrench is a little too big for the narrow place. Can anyone give some tips on this? Because today another misfire code P0305 just came out. I am afraid I have to take off the UIM again... I haven't check if the injector came bad. Hope not.
BTW: anyone knows the nut size that hold the bottom part of EGR guide tube? I lost one of them last time. I mean the inner size, M8 or M7 or M7.5? I know the outter size is 12mm. Thanks in advance.

MaxiNone

iTrader: (1)

i've had this similar problem. the funny thing is when the codes would be cleared the car ran like crap, huffing and puffing and caused the CEL to come back on. after light came back on, car ran normal and same code (#3 cylinder)