I30-low idle at stops-knock sensor&o2 sensor codes

[luisgofarrill]

Ok, I've been looking through the site for days now, and have gotten alot of information. Thanks.

I bought an Infiniti I30 about a month ago with a check engine light on. He told me it was and EGR problem. I pulled the EgR Valve, replaced it, and cleaned out the tube. Then I went ahead and cleaned the TB, and IACV, changed plugs and air filter. It still ran rough, so I ran some seafoam through it and it smoked like a siv. Now, when I'm in drive at a stop sign it idles down to 500rpm, enough for the check oil light to come on. If I give it gas, the check oil light goes away. Finally took it to get the codes checked and it said Knock sensor, O2 sensor (bank 2 sensor 1) and cylinder 5 misfire. I reset the codes, but the O2 sensor and knock sensor codes are still in. However, when I drive on the highway and rpms hit about 2000, it vibrates. Don't know if these are all related. I've also changed the oil and filter.

BAsically, where do I go from here. I've seen threads that say the KS could be a product of O2 sensor. I could possibly be misfiring, but the spark plugs look good, even after the seafoam clean. I've also seen that it could be the MAF sensor. So tonight, I'm going to clean the MAF sensor and see if it helps. Not sure if I should replace the KS or O2 sensor or both. Could I have an intermittant misfire on cylinder 5 that only shows when I get up to speed? Lots of questions, I know, but wanted to give as much information on what I'm seeing as possible. Thanks for any help you guys can give. I already feel 10 times more educated than I was a week ago just from reading this site.

[tigersharkdude]

coil pack on cylinder 5, and the O2 sensor. KS is usually a ghost code that pops up with other codes, you should pull it though and see if its cracked. Pulling the KS is like a 5 minute job ( you will need a ratchet, extension, swivel joint, and a 10mm or 12mm socket

[luisgofarrill]

Thanks. That's kind of what I was suspecting, so I ordered the coil pack and the O2 sensor and will be putting them in today if the weather doesn't stop being a pain in my a**. I alsor read how to pull the knock sensor using the method your talking about. I have to say, this sight is pretty awesome. I'm no super mechanic, but I feel with the knowledge that is on this site, I could literally tear my engine apart down to the nuts and bolts and put it back together again no problem....ok, maybe not, but you know what I mean. Again, thanks for the help. I'll let you know how it runs after I replace them.

[tigersharkdude]

What brand of coil pack did you order?

[luisgofarrill]

.....not sure now that I think about it. Ordered it from O'Reilly's. Is there a specific brand I should get that works better. It's supposed to be OEM. I was just in a hurry to get it cause car is really running rough and mpg is pretty bad.

[tigersharkdude]

was it about $75? BWD is what Im running, they are from o'reilly's and work great

[luisgofarrill]

yes

[luisgofarrill]

One last thought. The car has 305k original miles. When I cleaned the iacv, throttlebody, egr, and looked into the intake manifold, lots of carbon buildup. I'm wondering what kind of shape would the rest of the engine be. At 300k, should I look at just cleaning the IM and replacing gasket, rebuilding the entire engine, or theres a japanese engine mechanic that can put a jdm in it for $1900, which includes the engine and labor. And if I put a jdm in it, will it pass emissions? Are jdm's good engines, or do they drive those cars into the ground (which is why they are so cheap)

[tigersharkdude]

JDM engine? thats the same thing you got pretty much. A different intake manifold, and a few other things. At 300k, its a little high, but as long as the car has good up keep you should be decent. a rebuild will cost more than what your car is worth. Before I decided to drop $2,000 on a car barely worth that...I would start saving my money to get a lower mileage car. 300k is going to have some fair body ware and tare

[luisgofarrill]

Ok, so I changed the coil pack on #5 cylinder, and cleared the codes. Ran fine with no codes for about 10 minutes. Ran it up 10 110mph and down a couple of times. o2 sensor code went away. checked codes again. Now, I have a 1320 code (ignition signal primary), P0505 (IAC-AACV). I also still have the knock sensor code and A/T Communication Line code. I also checked for vacuum leaks, and I have one around the IM, and the TB. I'll replace those here pretty soon. My question is could those leaks be causing the p1320 code? The IACV code is intermittant, so does that mean I should pull it off again and clean it better, or replace it? Or could it be caused by having only 1 new coil pack. I'm also running brand new bosch plugs (bought them before I found out should be NGK)...could that cause the problem. I plan on fixing all of these as time and money permit, but can only afford to do a little at a time.

As a side not, my speedometer drops to 0mph every now and then. I just give the dash above it a thump and all works well...could this cause the AT communicaiton line code. only the mph needle drops to zero, but but doesn't impact the car.

[luisgofarrill]

as a side note...it definitely runs better with the new coil pack