just purchased a 2005 nissan maxima 147000 miles drove car 1.5 hours home but it had a miss and exhaust leak.i put car on computer got code p0300. I look car over found out they had coil pack wires crossed, when i got that right i got code p0301 i switch #1 cylinder with #2cylinder and i had no change still get same code p0301 and sometimes p0300 so i put new spark plugs in it still same code p0301 check compression on all cylinders they had 190-210 on all 6 cylinders all the coil packs are good and injectors are good i swapped the injector from cylinder 1 to cylinder 5 stlll same code. i took car to exhaust shop got exhaust leak fix on rear converter.then i drove it for a while and the car start losing all power couldnt go over 20mph i drove it home and look under it car the converter by firewall was red so i took it off and gutted it and it still wont run over 20mph

 

so i took the upper intake off and check over everything again getting fire to injector put spark plug in end of coilpack and it got good fire so i was going to take fuel rail off and turn switch on to see if fuel come out to make sure fuel rail isnt clogged but now when i turn switch on park lights come on and fuel pump do not come on

 

Yea if the catt is cherry red meaning a big misfire, by unburned gas.
Did you erase the dtc with scantool and then drove the car?
Should have checked which monitors were ready and which were not, that should have lead you close to the fault.

 

i erased code with scan tool didnt help. and what do u mean which monitors are ready

 

now it will not start up dont hear fuel pump come on how can i tell if its the nvis-nats

 

Let it cool down..if the cylinder temps. Exceed 260F-330F the ecu will shut all injectors for close to 2 hours to prevent damage. If you have a generic cheap scan tool that just shows codes it won't show you monitors.

Monitors- are test run by pcm to show which test have failed or passed for example evap, 02, misfires, egr....
This will point you to either your o2 monitor as 'failed' which will show o2's are acting up going extreme lean and throwing extra gas into cylinders because of exhaust leak, or misfire monitor leading to bad coil or injector. There is a million possible faults for this.
Now that you Guttenberg catt the rear o2 will show malfunction and throw another code for that as well.

 

Okay I still can't figure out what will cause a miss on cylinder 1 if the coil packs are firing and injectors have fire going to them and still not firing and have good compression what else is it to check

 

Okay I still can't figure out what will cause a miss on cylinder 1 if the coil packs are firing and injectors have foe going to them and still not firing and have good compression what else is it to check

 

How do you know the coil fires.
Did you take it out and grounded the spark plug to engine block and seen spark?
Next would be to measure voltage at injector with your multimeter. could be a harness connector problem too.
Use R pins and probe injectors.
DO NOT pin both connectors at injector if those touch the ecu could fry. Pin the injector volt and battery negative. Every time you turn key you should see voltage spikes. Meaning injector working if not then that's where you can start.
I would write those codes down and disconnect battery over night to erase memory.

 

*T pins

 

Yes grounded plug to block and got spark
When u use meter I got 9 volts and when engine turn over it drop to 7 volts I compared that one to all the rest of injectors Harness and got the same reading

 

Can u explain how to probe injectors

 

No problem.
Yea I'm getting ahead of myself, it has a reference voltage from battery when the trigger like crank sensor tell injector to open pcm grounds injector and pulses.
You can ohm them to make sure they have adequate resistance which can make injector not work properly. I believe around 12-18ohms is acceptable.
You can also do a ground to battery negative looking for as close as .01v
If those parameters are within I would check injector itself.
You said you removed and swap to cylinder 5 sometimes you can slap injector on intake manifold and mess up the flow rate it can still have voltage but not fire properly, hope that helps some.

 

To probe injector you have the connector plugged and use a pin behind to the power side and negative battery.
If that gets about 9v. the voltage drop from battery to injector is about 3v
Unplug connector and pin the power side again without injector this will show reference voltage as high as battery voltage. If that is proper than injector is mostlikely the cause. Pretty much is pissin and spitting a bad pattern of fuel causing mis fire

 

Thanks man that was very helpful,
No man I didn't learn ****.
Well damn! Ungrateful bastards

 

No man I'm not ungrateful i appreciate everything you are telling me. . Had to go back to work been on the road I drive truck s haven't tried the last post sorry if I offended u. But we need more people like u on the forums I will let u know the results when I get back home