Pain in the A** driver's side catalytic converter change

[fidelcastrol]

I have a 2006 path se with 124000mi and had the dreaded P0430 MIL code, so I swapped out the cat and fair warning to you guys the bolts that hold the heatshield to the exhaust manifold WILL BREAK OFF . No amount of PB blaster will loosen them. I couldn't get a drill in there to drill out what's left of the bolts so I had to use a worm drive clamp to strap on the heatshield to the manifold. Guys be ready cause the heatshield is a pain to remove and the cat is also hard to remove and manuveur from under there (4WD). Good thing is that the cat only cost me $140 shipped (front left) and a butt load of sweat and alittle blood and antisieze. My question to you guys is can I remove the heatshield and run without it on the exhaust manifold without effing something else up? The inside of the old cat looked good but I guess it wasn't good enough for the EPA (I hate tree huggers) lol.
By the way my truck has been in NC since new and the bolts on the exhaust are rusted up good so make sure when reassembling to use liberal amounts of antiseize.

[smj999smj]

I would not advise to discard the heat shield. If the bolts broke in the manifold, you could remove the manifold and drill out the old bolts and, if needed, install Heli-coils.

[fidelcastrol]

Thanks for the advice but nah I'm not pulling the manifold off just incase I break a stud in the head, could you imagine all the trouble that damn cat would have caused. I took a big radiator clamp and cut 2 slots in the heatshield and strapped in to the exhaust manifold. If that fails then I might just say fack it and jb weld that thing on.

[fidelcastrol]

FML the damn light is back again, now it's P0420, another facking cat. WTF did Nissan build these trucks with spit and crazy glue!!!

[deermjd]

Now that you've replaced one the other should be a piece of cake!

Odd that the cats on both sides would fail at almost exactly the same time. Most likely they are link somehow. Either something is directly causing the cats to fail or damaging the O2 sensors or causing the O2 readings to be out of range and trigger a CEL.

So to make sure I'm not confusing myself, you first got a P0430 code (bank 2, which is passenger side) and you replaced that cat, then you got the P0420 code (bank1, driver side)?

[fidelcastrol]

I don't think this is related but i installed an auxiliary fan on the transfer cooler and had to disconnect and remove the battery for a short period on time. Could this have somehow caused this 2nd mil light

[smj999smj]

Disconnecting the battery will usually cause a P0507 code when the idle air volume needs to be relearned or the VDC light to illuminate when the steering wheel position sensor memory is erased and needs to be relearned. It shouldn't cause a catalyst efficiency code to set. When the converter is removed, the inlet side of the catalyst media should be inspected for condition, including signs of burning oil or deterioration.

[fidelcastrol]

Yeah I suspected that, funny thing about the other cat I replaced, it looks perfect. I saved it just incase it turns out the cat was good and maybe I just got a small vaccuum leak or something else causing the MIL light. I put the OBD 2 scanner on today and found that the MIL light turned on @ 43MPH, engine load 63%, intake temp 127, air temp 101. So does that mean that it was the last time the vehicle was below spec. or was that just the first time. If it was the last time then that means I might just have a weak cat on it's way out and can ride for alittle while. The old cat had a small leak at the flange with the manifold funny thing is that I couldn't hear an exhaust leak but when I removed the heatshield there was soot under the it right at the flange. I hope this truck doesn't become troublesome cause I love the styling and the room and ride. I added an aux. trans fan for no reason cause it never gets hot enough to kick on.

[smj999smj]

The freeze frame data shows the conditions that were present when the code was set last. On a Consult II or III scantool, it will let the user know if it was the first time this code has set with a "1t" in the incident counter. If the code has triggered multiple times, it will give the number of times it has. There are probably some high end generic scantools that can do this, as well, but I can't tell you which ones. The converters likely just became inefficient if there is nothing out of the norm found on the media, ie burnt oil.

[fidelcastrol]

I just used the loaner scan tool from advance auto. Do you guys know if the cheapo scan tools on ebay from China for $50 are any good?

[fidelcastrol]

deermjd P0430 is driver's side cat and P0420 is passenger side cat on our vehicles. Truct me I thought it was the other way around and ended up buying both cats. But no worries cause I heard that when one goes out the other is not far behind and I seem to be proving that with mine. Guys, if I had a vacuum leak would my engine run rough or does the computer compensate and mask it?

[smj999smj]

It depends on the size and location of the vacuum leak. As far as the ECM, I think "compensate" is a more accurate word than "mask." If the ECM sees that the system is running too lean, it will trigger a system lean code, ie P0171 or P0174.

[fidelcastrol]

Yeah that seems logical. smj, are you a Nissan tech, you seem to know alot about these trucks?

[smj999smj]

I started as a new & used car detailer with Nissan at the end of 1985 and worked my way up to a Nissan Master Technician. I left Nissan in Oct., 2003, and moved from NJ to VA. I still do some auto repair on the side at my friend's shop, but my primary job for the past 5 years is a Corrections Officer with the VA Dept. of Corrections. It's a lot less headache!

[fidelcastrol]

Wow less headaches in DOC than Nissan! I also moved from NYC to NC, I got fed up with the crime, traffic, tolls, and taxes. Do go 4 wheeling alot up in VA? I'm looking for trails in my area, nothing too extreme I still have stock ride height. Quick question, can I run 265/75/R16 on my SE it is not the off road but I see that is the stock tire on the off road pathy or should I stick to 265/70/R16 it's a 2006 SE 4x4.