Driving with a cylinder misfire > kill the CAT?

Status
Not open for further replies.
Z

zorobabel

Joined
Jan 27, 2011
Messages
1,245
Location
Roseville, CA
It looks like the Maxima developed a misfire at lunch today.
Is it ok to drive it like this for about 11 miles? How about if I also unplug the power from the injector? It might be burried under the intake manifold, so it might not be doable.
 
i doubt a 97 nissan is smart enough to automatically disable the fuel injector like some newer cars do when a misfire is detected so if possible, you should disconnect it. then you can drive as long as you want and not have to worry about a thing. i would drive or run the vehicle as little as possible otherwise because especially on a high mileage vehicle with an already worn cat it doesn't take much to kill it. and california certified cats are waaaaay expensive.
 
Last edited:
I wouldnt drive it unless its an emergency until its fixed. If you have to pass cali emmissions you could end up scrapping the car due to repair price if you end up damaging it by running with misfire.
 
Originally Posted by Blkstanger
Do you have a code reader so you know which cylinder it is?

P0303 - right in the middle of the rear bank unfortunately.
 
If you can disconnect the fuel injector wire so it doesn't fire fuel into that cylinder it's ok short-term. Otherwise don't drive it.
 
Last edited:
Replace ALL 3 fuel injectors in the back (1/3/5). Get one of these brands:
Bosch 62027
Hitachi FIJ0023
Beck/Arnley 158-0861

These injectors do NOT come with O-rings, so you will have to purchase separately. Use Beck/Arnley part number 158-0957. You need a package of O-rings for each injector, so if you replace 3 injectors, you will need 3 packages of O-rings.

You should also replace the valve cover gaskets (Beck/Arnley or Mahle/Victor Reinz), the intake gasket (Beck/Arnley), and also clean out or replace the EGR guide tube

The screws for the injectors will be galled, so you have to take them off with a vice grip around the screw in order to remove it. Replace the screws with Hillman #4402. The Hillman screws have a hex key, so you screw and unscrew them with an Allen key. About $10 for a box of 10.
 
How do we know its and injector issue? Its a P303 and just as likely to be a plug, boot or COP. Correctly diagnosing the problem comes first before chucking parts at it.
The SMP FJ151 is a Denso and comes with O rings. SMP does not manufacture injectors. The T series is Chicom.
 
I believe Nissans of that generation had coil issues at high miles. The next generation had coil issues at lower miles. I had one of each, coils were one of the few things I had to repair.
 
Originally Posted by Trav
How do we know its and injector issue? Its a P303 and just as likely to be a plug, boot or COP. Correctly diagnosing the problem comes first before chucking parts at it.
The SMP FJ151 is a Denso and comes with O rings. SMP does not manufacture injectors. The T series is Chicom.


Originally Posted by CBR.worm
I believe Nissans of that generation had coil issues at high miles. The next generation had coil issues at lower miles. I had one of each, coils were one of the few things I had to repair.


Only the 99's had coil issues in the 4th gen. The 95-98 Maximas and I30s almost never have bad coils.

OTOH, fuel injector failure is VERY common on these cars! It is usually caused by a broken pintle cap.

In addition, the 4th gen Maxima's intake has cutouts for the rear plugs and coils. So it would be very easy to switch coil #3 with coil #1 and see if the P0303 remains or switches to P0301.
 
How is a broken pintel cap cap going to cause an injector failure? These injectors use an open cap, if the cap failed on a side feed injector like these it could cause the lower o ring to be pushed down in the rail and cause a massive leak into that cylinder but no damage to the injector would occur although hydrolock in that cylinder is a real possibility.

Pintel caps on top feed injectors many times have nothing to do with spray pattern but are there only to hold the o ring on when it is removed, I have never seen a broken cap damage an injector.
The model of side feed used in this engine are very reliable, the damage I see most with these is damage resulting from improper removal.
 
Thanks for the great replies!
I got to the car (wife had it today) and cyl #3 injector is the only one with no hope of access
frown.gif
. Called AAA and while waiting for the tow, I swapped coils 1 and 3 and let it idle for a while. No change: rough running, white smoke and gas spewing out the exhaust. Didn't throw a new code for #1.
After the tow, I idled it some more, and no #1 code. I changed the #3 spark plug with one of the plugs I took out about 10000 miles ago, idled it some more, no change. Unplugged the coil harness connector for #3 - no change. I unplugged the coil harness connector for #1 - slight change. I checked voltage (actually a friend helping me did this) on the harness connector + worked, G worked, IB showed same as +; not sure what that IB does, but my multimeter didn't catch any pulsing on it. After all the idling, there was a strong smell of gas and a puddle of gas under the exhaust.
It looks like injectors or ECU at this point to me...
 
On Nissans the check engine light usually flashes (instead of steady on) if a misfire event is occurring that could potentially damage the cat. I had both steady on and flashing misfires occur on an Altima (and the code reader did show a random misfire code).

I ended up fixing the misfires by cleaning out the EGR passages in the intake manifold.
 
It sounds like you may have lost the pintel cap and the o ring moved down and is leaking fuel into that cylinder or a lower injector o ring failed or the injector is stuck open. Loosing the cap does not mean the injector is defective.
If its sticking open its best to replace it. I have caps and o rings for these if you need them.

I doubt you have an ECM failure, the above is much more likely.
 
The CEL wasn't flashing. I should also add that at 155k (20 months ago) I cleaned the EGR, changed intake gasket, valve cover gaskets and much more.
 
Originally Posted by Trav
It sounds like you may have lost the pintel cap and the o ring moved down and is leaking fuel into that cylinder or a lower injector o ring failed or the injector is stuck open. Loosing the cap does not mean the injector is defective.
If its sticking open its best to replace it. I have caps and o rings for these if you need them.


Thanks Trav! How would I tell if an injector is stuck open?
 
Originally Posted by slacktide_bitog
Replace ALL 3 fuel injectors in the back (1/3/5). Get one of these brands:
Bosch 62027
Hitachi FIJ0023
Beck/Arnley 158-0861

These injectors do NOT come with O-rings, so you will have to purchase separately. Use Beck/Arnley part number 158-0957. You need a package of O-rings for each injector, so if you replace 3 injectors, you will need 3 packages of O-rings.

You should also replace the valve cover gaskets (Beck/Arnley or Mahle/Victor Reinz), the intake gasket (Beck/Arnley), and also clean out or replace the EGR guide tube

The screws for the injectors will be galled, so you have to take them off with a vice grip around the screw in order to remove it. Replace the screws with Hillman #4402. The Hillman screws have a hex key, so you screw and unscrew them with an Allen key. About $10 for a box of 10.

Thanks for the detailed post!
 
Status
Not open for further replies.

Similar threads

J
Odd misfiring and codes on a VW VR6
Replies
17
Views
383
i6pwr
Number_35
2007 Honda Pilot 3.5 multiple misfires
2 3
Replies
53
Views
3K
Number_35
A
mystery misfire issue?
2
Replies
38
Views
2K
adventureboss
S
oil found on spark plug threads
Replies
4
Views
771
snowshew
1911CHAMPION
Intermittent misfire 2019 Ford F-150 2.7 Ecoboost S-Crew 4x4
2
Replies
34
Views
3K
panthermike
Back
Top Bottom