silverTA2002

iTrader: (1)

Ever since I did the heads/cam package just over a year ago, I've been through 4 o2 sensors on bank 2 (passenger side). What the crap??

What would keep killing the sensor on only one side? I've checked for leaks, and there aren't any on that side.

It just seems unusual that 4 would die on the passenger side, and the driver's side is completely fine.

For spark plugs, they only have 10k miles on them. NGK TR6 plugs.

Any help? I think I'm out of my one year warrantee on the o2 sensor. I really don't want to have to shell out some $$.

DaddySS

What code are you getting?

silverTA2002

iTrader: (1)

No code. Car will just start running (smelling) really rich.

If it goes real bad (like now), I get bad hesitation when I give it part throttle under 2k rpms.

When I log the car, the bank 2 o2 sensor will barely switch at all (stays around 450-500 all the time right now) and my LTFTs go real negative at part throttle on bank 2 (-15 or so).

I'm kinda surprised it doesn't throw a code for insufficient switching. But it doesn't.

ArcticZ28

iTrader: (14)

Did you get a tune? If so, they may have shut off some of those codes. If not, are you using the proper 02's for the fronts? The best ones to use are the Corvette rears (Bosch part number 13111). Definitely sounds like there is a leak somewhere though.

98TA_vert

a buddies car kept doing the same thing switched to the 13111 and its been a year now and everythings still fine, but he's LT only

fastest94v6

iTrader: (10)

def. get that tune checked out!

silverTA2002

iTrader: (1)

I do all my own tuning. LTFTs are all right at -2. WOT fueling is right at 12.8:1.

I'm on my fourth set of Bosch 13111's on bank two.

Anyways..... If it were the tune, then I "should" be killing o2 sensors on both banks.

Bank 1 has never been replaced in a year and a half, and still switches properly. Bank 2 only is the one that keeps dying.

The only o2 codes I deleted were dealing with the rear o2 sensors (which are gone now).

The issue the 13111's clear up has to do with the heating of the front o2 sensors. I don't have that code problem anymore. Just dead o2 sensors.......

silverTA2002

iTrader: (1)

Anyone else out there with this problem?

ArcticZ28

iTrader: (14)

Did you mess with the wiring at all when switching O2's? You've obviously been under there a good amount in changing them out but are you sure the wiring isn't melted or pinched somewhere up toward the header/harness area?

headsupkid01

Maby theres a prob. with a injector or two on that side. weird s**t can happen when you take that much of your moter apart.

eallanboggs

iTrader: (1)

Doesn't logic tell you 4 02s don't go bad on the same bank one after another? You question points to the answer. Your 02s weren't failing BEFORE the head/cam swap, but now they are? Very curious indead! Also the fact that only Bank 2 is causing a problem, but Bank 1 appears to be OK. If you don't have any DTCs how have you determined 4 02s are defective? Have you tried installing one of the "defective" 02s into Bank1 to see how it works? I'll bet you don't have 4 defective 02s. You just have 4 good spares that will be setting on the shelf in the garage for a long time. You go RICH(fuel smell) so the PCM says shorten the injector pulsewidth(go lean). When it does your log shows negative LTFTs(-15,-2). You interpret that as a defective 02 on Bank 2. Maybe your PCM is doing it's job by trying to keep your fuel trims within EPA standards. The PCM won't set a DTC and turn on your SES until your tailpipe emissions are 1.5 times the EPA FTP standard. Have you looked at Mitchell or Alldata or even a GM shop manual for low switch activity on the pre-cat 02s? That's a starting point, but I'd go back over your work first. Vacuum leak comes to mind right away. Did you read your spark plugs? Have you checked the connectors going to the coil packs and fuel injector? You have left something disconnected or unplugged or not torqued properly.

silverTA2002

iTrader: (1)

Nothing is melted through. But, I don't think that's the problem because when I switch the sensors (one side to another or a new sensor) it will work fine for a few months.

silverTA2002

iTrader: (1)

"If you don't have any DTCs how have you determined 4 02s are defective?"

The car starts running rich/poorly. I log the car with HP tuners and bank 2 will no longer "switch" properly, it just hangs around 450-500 instead of switching from 50-800 or so like it should and Bank 1 does. This causes WAY rich LTFTs (-15 or so) on bank 2.

When I swap o2 sensors from bank 1 to bank 2, the problem moves with the BAD sensor to Bank 1.

Trust me, it's a bad sensor. I'm not sure why it doesn't throw an improper switching code.

Also, I only have one spare (the stock one that went bad). The rest were exchanged using the 1 year guarantee.

When I put a NEW GOOD sensor in. The problem goes away for a few months. Last time it lasted 6 months.

What I'm trying to figure out is what is KILLING the sensor on one side only. (well I have killed one sensor on bank 1 in 5 years).


I'm betting it has something to do with the heads/cam install. I don't want to, but I think I'm going to have to pull the spark plugs on that bank and start there.

Where should I check for a vacuum leak?

"Have you looked at Mitchell or Alldata or even a GM shop manual for low switch activity on the pre-cat 02s?"

Not yet. Any links online to the shop manuals?

silverTA2002

iTrader: (1)

I hope not. But, it was a little scary being down to the block in my garage during the install.

Wouldn't that show up in my log, or throw a code if this were the case?

I'd think my fuel trims would be way different if an injector were bad. When I have 2 good o2 sensors in there, there's only a 1-2 difference in LTFTs between the banks.

silverTA2002

iTrader: (1)

I should mention that the last time I "read" my sparkplugs was a few months after the heads/cam swap.

I was using NGK TR55s. After only 3 months, they were reading slightly too hot. So, I switched to TR6 plugs. There was no noticeable difference between Bank 1 and 2.

eallanboggs

iTrader: (1)

I'll look up low activity in the GM shop manual and tell the what action is suggest you take. Have you checked the intake bolts, hose to power booster, other vacc lines, caps on bungs on the intake, etc.? Do you have driveability issues or is it that your log shows you LTFTs are lean on Bank2?

eallanboggs

iTrader: (1)

There are two DTC that describe your symptom even though your SES isn't lit. They are 02 Slow response and 02 Insufficient Activity. The troubleshooting tables are too long to transcribe here so I'll list some of the important things to check.
Exhaust Sytem leak
Faulty 02 sensor connectors
Faulty sensor wiring(open or shorted 02 harness wire)
The shop manual goes into extensive testing of the 02 sensor circuits. I can't list them all here. If you beleve this is your problem you need to get the manual and do these tests. I don't think this is your problem. The DTC you want to look up are P0133 and P0134.

silverTA2002

iTrader: (1)

Well, here's an update. I killed another sensor on Bank 2.

I know the sensor goes bad when my car starts driving like crap at part throttle.

Then I log, and sure enough, my LTFTs and STFTs are like -15 on bank 2, and -1 on bank 1. Plus, bank 1 is switching properly at idle, and bank 2 is staying around 450-600.

No code again. But based on the log, it's obviously another killed sensor.

Since I'm out of warrrantee, I tried the propane torch "trick" and took about 1 minute on the torch to burn off all the carbon.

I logged again, it didn't fix the problem. Interesting thing though, when the sensor isn't reading properly, and the car is driving like crap, my Injector pulse is about 3.2 on the driver's side and 2.8 on bank 2. That'll definitely screw up the fueling.

Looks like I'm shelling out more dough for another year's worth of sensors...... Since it fixes the problem, every time, for 3 months.

Also, I'm going to change all the spark plugs at the same time, in case that's a problem that's killing the sensor. I dunno.

ArcticZ28

iTrader: (14)

Are you SURE there are absolutely no exhaust leaks before the 02? That would do exactly what you are describing. With a leak, it dumps fuel b/c the 02 reads leaner than true, which causes it to die. However, it won't be noticeable necessarily with tuning, as the 02 will be commanding more fuel to get the right reading, so it will look like it's the right A/F, but obviously won't be because the car is running like crap from the extra fuel.

eallanboggs

iTrader: (1)

I told him to check for exhaust leaks over 2 months ago. He still thinks his O2s are going bad faster than milk spoils in the frig. The guy at the parts counter must love it.