Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hi, My name is*****'m happy to help you. During our conversation, I may be presenting you with different things to try, and ask you some Questions to get a better understand of the issue so I can answer your question properly. So stick with me to the end, and I am sure we should be able to get this issue resolved for you!
When I see a P0300 or a P1320 code with a running issue, that is a Distributor issue. If you replaced the Distributor with one from your local auto parts store, they never work right. You would need to get a distributor from the dealer. Also, if you changed the spark plugs, make sure you used NGK spark plugs. These engines don't like any other brand spark plugs, especially Bosch!
If you have any more questions on this, please feel free to ask.
If not, and you're satisfied with my help, please Rate me. I hope I have provided you with Excellent Service.
Wow, and you still are getting those codes.. Did you change the spark plug wires also?
Did you change a Knock sensor or something also?
Did you just get this truck? How long has it been running like this?
Ahh.. ok.. So it's been that long.. Do me a favor. Go on the passenger side of the trucks engine. There are two 02 sensor connectors. I have seen when doing a knock sensor these can get crossed. When they get crossed, it runs like crap!
You can either simply try swapping those two plugs, or go tell me the wire colors to Bank 1 Sensor 1 02 sensor wire colors are so I can see if they are plugged in right for you.
02 sensors. A/F sensors came out in 06 or 07 Pathfinders.
That is Bank 1 Sensor 2 02 Sensor. Follow that down and make sure it's on the passenger side
That is correct. So the rears are good.
The only other thing that I have seen is a clogged up Catt restricting exhaust flow. That won't allow the engine to breath right and can cause Misfire codes as well.
Has that been checked?
The only real way is to drop the exhaust to inspect it.
What I do is remove the front 02 sensor, and shine a flash light into the exhaust and then look on the other end where the 2nd pre-catt bolts to the catt and see if I can see light shining though.
You have 2 primary that are monitored that bolt right off the exhaust manifold. Then you have two pre-catts that are not monitored.
It's not to common. but when I see these trucks with high mileage it can happen
That is not common. You can certainly check fuel pressure. You should have 36 psi of pressure. These trucks didn't have to may fuel pump issues.
I don't know why everyone jumps to think TPS. These TPS's never fail! I mean in my 20 plus years working for Nissan, I can't tell you how many I have working on and I think I can count on one hand how many I have seen go bad. I have replaced more after market ones that were installed cause people think it goes bad and just changes them.
Well you want to start from the basic's.
First checking fuel pressure if you like. Also make sure the fuel filter is good and not clogged. That is located above the rear diff.
Then if you have access to a scanner, monitor fuel trim readings and graph 02 sensors and you maybe able to see if the catt is clogged or not based on the front 02 sensor readings.
They will read zero, but should switch every so often then go back to zero
Oh.. They should never be Zero.. The only time I normally have see the front 02 sensors flat line is when a after market MAF sensor is installed. They tend to never meter air properly and can flat line 02 sensors.
Do you know if it's oem or not?
If you are building to much back pressure due to clogged catts, the 02 sensors won't read any flow which can make them read steady and zero, cause they can't switch rich to lean
That sound almost like a bad MAF sensor based on the rpms your telling it's bucking at
Well I certainly am not a fan of after market parts, so it's good you put a OEM distributor in. How ever, after market Maf sensors never work right. If you even get one that meters air properly it will flat line 02 sensors and cause running issues. So that may not have helped your situation.
Do you know if this had a engine put in?
Hard to say with out seeing readings. I normally graph these type of issues. You can certainly unplug 02 sensors one at a time and see if the running issue changes at all. Since the truck had a knock sensor done so long ago, and it's been like this ever since, you could have a vacuum leak also. That can certainly cause a misfire also.
Can you grab the EGR diaphragm and lift it and stall the engine when it's running?
Ok, so the Egr is most likely good. The truck idles ruff doesn't it?
Think you can take a video clip on how it idles and revs up. Also span over the 02 sensor connectors on the passenger side. It sounds so much like the could be backwards, but based on the info, it does't sound like they are.
As I said, I am not a fan of after market electrical parts cause they never work right and can have you spending money on things you don't need to spend time or money on. So I would certainly work on putting as much as you can back to OEM.
I would certainly put OEM sensors in and I would make sure the MAF sensor is OEM also.
They are all important.
The compression should be all around 5 PSI from each other, which is what you have. But bank 1 has that to high. Did you check compression with the fuel pump fuse removed?
You can have compression, but have a bad leak down. This sounds like something that will require more hands on to determine with a scanner.
I will re-open this question back up to see if anyone else can help you with this.
Please do not reply as it would take it out of Que..