really need help. 01 Altima

austin286 · #1 (**permalink**) 11-09-2009, 11:57 PM

I have had a rough idle for a little while now and replaced catalytic converter, valve gasket, tested intake manifold gasket with carb cleaner and as far as i can tell its fine. I have a freeze fram code P0304 and pedning code P0300. spark plugs, cables, distributer cap and button all new. any ideas? im bout to take it to Napa to have it looked at but dont really want to. any help would be great!!!!!!!

austin286 · #2 (**permalink**) 11-10-2009, 12:53 AM

took spark plugs out and their is some oil on the threads of a couple of them. would this matter?

reszno · #3 (**permalink**) 11-10-2009, 01:15 AM

I would check the injectors. My bad injector never threw a code though. My # 4 injector went out after I changed the fuel filter. I could really notice at higher speeds.

austin286 · #4 (**permalink**) 11-10-2009, 12:21 PM

checked fuel injectors all reading a resistance of 9.2 ohms close enough to 10 where they shoud be. even took them out and they appear good.

**jserrano** · #5 (**permalink**) 11-10-2009, 02:17 PM

That test still doesn't entirely rule out a bad injector cause there are other things that can go bad with them. An injector could be totally or partially clogged...could be leaking...could go bad under normal operation...etc. The test only tells you that the static coil resistance is good, period. But lets assume they're good.

The P0304 means a cylinder #4 misfire. And a P0300 means a multiple cylinder misfire. You have to clear the codes after you replace parts and see what codes comes back.

A P0300 is typically due to a lean or rich misfiring. And it has to be from something common to all cylinders. See if the spark plug gives any indication or check what the scan tool reports for the short- and long-term fuel trims values.

austin286 · #6 (**permalink**) 11-11-2009, 02:53 AM

gave my car to napa for diagnostics testing and they sure taking their time. been their for atleast 12 hours with them testing it. They have told me however, the problem is with the ignition system and the EGR system. does this make since?

austin286 · #7 (**permalink**) 11-11-2009, 12:56 PM

napa said my EGR Solenoid is bad and that a Spark Plug in Cylindar 4 is bad but told them thats i have replaced my plugs 3 times in the last year so they are looking at that part again. asked them to look at vacuum leaks as well. anything else they should look at? Does it make since for a P0300 code for the EGR Solenoid?

**jserrano** · #8 (**permalink**) 11-11-2009, 03:03 PM

Quote:

Originally Posted by austin286

napa said my EGR Solenoid is bad and that a Spark Plug in Cylindar 4 is bad but told them thats i have replaced my plugs 3 times in the last year so they are looking at that part again. asked them to look at vacuum leaks as well. anything else they should look at? Does it make since for a P0300 code for the EGR Solenoid?

If the EGR valve stays opened then it can cause the bad idle and P0300. But the EGR solenoid valve is a long shot. And it would have to be bad that it would constantly cause vacuum to the EGR valve and that would also keep it opened.

Keep us posted.

austin286 · #9 (**permalink**) 11-11-2009, 03:51 PM

after telling NAPA about the spark plugs, i had them check for vacuum leaks since the altima 01 has an intake leak around 3 & 4 for most, and it came back positive. so ill be reaplacing it and the solenoid anyways. could the solenoid be bad though? i know its a long shot but could it be? How can i test the egr to see if it is?