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I fabbed up a home-made exhaust back pressure tester and went to town lat night. Bank 1 was a breeze, and I didn't get any readings, other than when lifting off a throttle it registered 2 psi.
In comes bank 2. I could not get that o2 off for the life off me. Ended up soaking it in PB and warming it up by running it a few minutes, then cranking on it with everything I had (which ended up being my big jack handle attached to a 1/2" breaker bar). Pic below. It finally cracked and i eased it out, only to find out the threads were destroyed/cross threaded by either infinit or whoever changed them last (they looked like stock Nissans at 240k). I was hoping the bung was ok, but, as luck had it, it was also jacked up. Got a thread chaser from AZ last night and it was worthless. Picked up a tap from Oreilly's today and spent several hours trying to ray-charles-tap it from above. What a major pita it was. I'm including some pics of my concoction below. I was finally able to thread the new O2 in and snugged it up. I was beyond happy i didn't have to take that driver side header off... I did do a quick back pressure test with my home-made tester and it only picked up like 1 psi at around 2-3k rpm.
I do hear rattles from the driver side cat (confirmed by jacking the car up and giving it a listen), and it finally blessed me with a P0430 code. I erased the codes and will drive around for a few days to see if it pops back. My B2S2 is doing crazy stuff. Screen below (green is b2s2). I will switch rear O2s around and see if i get any different readings on the banks. Great video on cat efficiency (P0420/30):
My B2 appears to be doing exactly what the bad cat in this video is doing, tho he only speaks about "efficiency" and not exhaust restriction.
I also scoped the cat on that bank (pics below). The honeycomb is still there, but there is a visible gap on one side, as well as, what appears to be, some kind of shrapnel damge inside the exhaust pipe (looking down thru the o2 bung hole).
accelerating in the street
idle
steady revs in park
the final boss
rip o2
tap-tap-tap
in the hole, drilling
scope pics of the b2 cat. looks separated on the side(s).
shrapnel damage? looking directly thru the o2 hole
Last edited by 99zx2turd; Jan 12, 2022 at 12:15 AM.
For the future the cats can sometimes be a breeze to remove, it depends a LOT on where you live.
The two forward facing bolts are reached pretty easily from the engine bay, you will need 36" worth of extensions and a swivel though, soak thoroughly in PB blaster, use only 6 point sockets. I typically break them by hand instead of using an impact since I still have not found a legit impact-rated 3/8 swivel that has the necessary amount of angle. 1/2" stuff won't fit, too tight on the driver side around the steering shaft.
yeah, been reading all about it. i've actually snapped a china freight 3/8 "impact-rated" swivel while extracting the b2 upstream o2 lol
the driver side cat is def done for, it's just i'm not sure replacing it will fix this issue. When cold, both rear O2s read the same voltage, right around 0.4v, but when hot, the driver side one goes haywire.
I was able to find two more threads that resemble my issue that turned out to be cats, esp. the hyundai one:
i did go ahead and order some aftermarket cheapo cats. like these: EPA Approved Catalytic Converter for Infiniti G35 3.5L 2007 2008 Left&Right | eBay
was thinking about getting test pipes, but it's my daily, and if anything, i want less noise not more (have my turbo rig for all that). will see what kind of welds these suckers have. will be spraying those bolts all week and hopefully get them and swap them in by the end of next week. been reading ont he 50/50 mix of atf/acetone and people swearing by it. i've always been a pb blaster kind of guy, but willing to give this mix a try. thanks for sticking around!
I'm sort of on the fence about test pipes, for one I appreciate the lack of gasoline smell and pollution. But the environmental impact of mining precious metals to make them, plus the added complexity to the engine control feels to me like it could go either way as far as whether it's "worth it" or not.
I'm ok with test pipes though, but be aware you would almost definitely need to add a resonator to the mid-pipe, there's plenty of room and it will quiet down all the obnoxiousness of test pipes on a stock muffler. However you MAY end up with a catalytic efficiency error code which can either be tuned out or usually corrected with a couple non-foulers.
I'm sort of on the fence about test pipes, for one I appreciate the lack of gasoline smell and pollution. But the environmental impact of mining precious metals to make them, plus the added complexity to the engine control feels to me like it could go either way as far as whether it's "worth it" or not.
I'm ok with test pipes though, but be aware you would almost definitely need to add a resonator to the mid-pipe, there's plenty of room and it will quiet down all the obnoxiousness of test pipes on a stock muffler. However you MAY end up with a catalytic efficiency error code which can either be tuned out or usually corrected with a couple non-foulers.
yeah, i was only looking at resonated test pipes, but even those were a toss-up as far as how it would sound on the tiny stock exhaust once you mate it up to those bigger (2.5") pipes. i had it down to berks, since you can still get those and not break the bank, but someone sent me a link for these aftermarket cats. as long as the welds were done by someone who at least finished welding school, we should be good to go. i'll post pics once i get them in. i might still need the anti-foulers on these, we shall see. i remember using those on my other car before it was turbo and they worked well, but it is a much older and less sophisticated vehicle lol
I usually buy 4 total non-foulers, try just a single and see if it works, if you still pop codes then take the second set, drill out the hole much larger (since you are just trying to move the sensor further away from the flow of exhaust at that point) and install the drilled set into the one already in the pipe.
Note, only ever do this for the downstream sensors to correct catalyst efficiency codes. Never EVER do this to the upstream A/F sensors
cats coming tomorrow night. after reading and seeing (youtube) so many people having nightmares with the demon bolts, decided to presoak them a few days ago. started with pb on sunday, then drove it yesterday, and soaked some more in liquid wrench today. my craftsman impact swivels came in today, so i put the 3/8" on to test right away. driver side was a bit stiffer, but booth took less than 5 minutes with just extensions and a small breaker bar. spent more time chasing down the extensions i dropped on the passenger side... attaching the pic of the rig below. hopefully the nuts on the studs go just as smooth.
I honestly think that most of the struggle with those bolts is not using that method. PB Blaster thoroughly, 6 point socket with swivel and FROM THE ENGINE BAY. Glad you got them off, make sure to check torque spec when reinstalling it's like 42 ft/lbs??
Also, be careful on the passenger side, STRONGLY recommend disconnecting the battery because if you drop an extension it can lay across the starter post.
well, the ebay cats are on. both demon bolts ended up snapping their heads off during removal lol was fairly easy process overall. the welds looked ok, but the fitment is so-so. still, for $200 some dollars, this cannot be beat. driver side cat was loose as a wizard's sleeve inside. was definitely on its way out. the rear honeycomb or whatever it is was sliding up and down with a push of a finger.
I've managed to mangle my oil pan in the process, tho (jack slipped off the brace and onto the pan while jacking her up) and had to wait an extra day before i could test driver her, as the oil was leaving the pan rather rapidly lol
got the new pan on today and took her out. first rev to 7k+ in 1st she was almost losing traction in this cold weather lol drove beautifully for the first 15 mins or so. many wot pulls to the redline without an issue, but then the hesitation started returning. first tell-tale sign it was back, was that the rpm were not climbing nearly as fast as few minutes ago (1st gear test). i pulled off to the gas station and added more fuel, as it was getting near E. when restarting the car, it pulled strong once again (1st gear), but a few minutes later was falling on its face. i've done some data-logging and attaching some graphs below. you can see it's going leaner and leaner as the time progresses. both banks report lean, as measure by torque (wrong voltage, roughly 2x as high as what it should be - 2.2v or 14.7:1 afr at idle). at this point, it makes me think it's something fuel related. i wouldn't mind putting a new pump in her at this mileage, but hate the fact that i'm starting to throw parts it her. still no codes.
Last edited by 99zx2turd; Jan 21, 2022 at 08:36 PM.
Ok here's what you posted before I fat fingered and screwed up your post...
well, the ebay cats are on. both demon bolts ended up snapping their heads off during removal lol was fairly easy process overall. the welds looked ok, but the fitment is so-so. still, for $200 some dollars, this cannot be beat. driver side cat was loose as a wizard's sleeve inside. was definitely on its way out. the rear honeycomb or whatever it is was sliding up and down with a push of a finger. I've managed to mangle my oil pan in the process, tho (jack slipped off the brace and onto the pan while jacking her up) and had to wait an extra day before i could test driver her, as the oil was leaving the pan rather rapidly lol
got the new pan on today and took her out. first rev to 7k+ in 1st she was almost losing traction in this cold weather lol drove beautifully for the first 15 mins or so. many wot pulls to the redline without an issue, but then the hesitation started returning. first tell-tale sign it was back, was that the rpm were not climbing nearly as fast as few minutes ago (1st gear test). i pulled off to the gas station and added more fuel, as it was getting near E. when restarting the car, it pulled strong once again (1st gear), but a few minutes later was falling on its face. i've done some data-logging and attaching some graphs below. you can see it's going leaner and leaner as the time progresses. both banks report lean, as measure by torque (wrong voltage, roughly 2x as high as what it should be - 2.2v or 14.7:1 afr at idle). at this point, it makes me think it's something fuel related. i wouldn't mind putting a new pump in her at this mileage, but hate the fact that i'm starting to throw parts it her. still no codes.
Last edited by cleric670; Jan 21, 2022 at 08:00 PM.
Here's what I would do, first thing is pull and inspect the plugs for some obviously different plug.
Next, do a pedal dance ECM reset, drive for a bit and see what long term fuel trim is doing.
Install the VQ fuel port sandwich adapter so you can get accurate fuel pressure readings AND pull the fuel pump to see if the strainer baggy has a lot of sediment.
Smoke test intake AND exhaust for leaks. Clean MAF, verify PCV valve is rattling.
If still misbehaving, compression and leakdown to rule out a more major issue ...
And I would do them in that order. This is all assuming you can do the repairs yourself, if you are paying shop labor hourly rates go straight to Nissan for a 1hr diagnostic. Consult 3 is a huge timesaver, someday I hope to own a Consult diagnostic tool...
i was able to find an '07 sedan at a local lkq and pulled a pump out of it this morning. $30 - not too bad. i took mine off and here's what it looked like. never seen so much corrosion and rust on a pump before. the tank itself didn't look too bad - the gas didn't have any sediment. the bottom of the tank did have some specs of rust. i always run 100% gas in her, and my turbo rig is also on pump gas from the same station and doesn't have any rust problems, so this must've been occurring before my time. i went out and test drover her with multiple wot pulls and she is pulling strong. updated afr graph below. looks like 12.3-12.5 avg at wot now. i'm a bit skeptical of the "new" pump, since i have no clue how many miles it has on it. any recommendations for a good aftermarket pump? thanks again for sticking with me thru this, Cleric.
the funniest thing of this all is that my girl called it right away. she's as car illiterate as one gets, but she was sitting on the couch one night reading about this and blurted it out. i was like, "yeah, it'd be hilarious if you are correct" and whaddya know...
