Elmore055

I have an 01 grand Cherokee Laredo 4.0 v6 95,000 currently throwing codes p0300 p0161 and p0355 I know what each code means and what they are for. I plan to do a tune up and replace the O2 sensor hopefully that takes care of these. But if I'm completely of course please feel free to correct me. Anyone ever had this combo? My jeep runs fine and doesnt even feel like its missing at all never stalled, idle never drops and never started hard. Just wanna hear your input or if you've experienced these issues together. Also today my check engine light flashed a couple of times, the weather here is now below 30 degrees.

dave1123

Welcome to CF.

I think if you'll check, your 4.0 is an inline 6, not a V6. I cannot find a listing for the P0355 code. Change the 02 sensor, clear the codes, and see what happens.

Elmore055

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Sorry about that I typed it up quick and it autocorrected on my phone, didn't notice it til the above comment and yours. Yes it's an i6 thank you for the input! And my mistake on the code it's not p0355 its p0305 for cylinder 5 misfire.

dave1123

I didn't mean to get pissy about the I6-V6 thing, it's just we've seen it too many times. It's like "did this guy even open the hood?" My bad.

It appears the 02 heater isn't functioning or the wiring isn't making contact. As I said, change the sensor checking the plug for good contact and see if the codes come up again. The 02 sensor doesn't function until it reaches 600* and the output is in MILLIVOLTS. Good clean contacts are necessary.

I personally use Bosch sensors because they come with the plugs installed, you don't have to splice wires. Check out rockauto.com

Elmore055

I have a Bosch downstream O2 on the way and all new spark plugs also coming. Hopefully those do the trick. I'll clean everything up too.

Elmore055

And no you're fine no offense taken! Haha that was a typo on my end.