Raoul-Duke

iTrader: (6)

Hi guys,

So long story short. When I installed my TSP true duals back in December on my 01 Z/28. My buddy cut off my rear o2 sensors that were just zip tied to something (previous owner).

Shortly after, I threw those two 02 codes, being the rear two, after having it scanned.

I just recently had my ECM re-tuned but before hand I had the codes re-read a second time and from December it is now showing all four 02 sensors being thrown. (front as well)

So could have the rear 02 sensors thrown off the front two?

I know sensors go bad, but what are the odds of the front two going bad at the same time?

I think its funny that before touching the rear o2's I had no problems whatsoever.

The car only has 76k on it.


Any info is greatly appreciated.

D14HUGGER.ORANGE

What do you have done to your car? Did you get your car retuned on the dyno after the mods? Your probably running really rich causing you to foul out your o2 sensors. Exhaust leaks will also cause it. When I install my headers and ypipe after bottoming out on every speed bump, 3months later it caused a exhaust leak on my ypipe and band clamps which fouled out left upper bank o2. On my 99 I have a fast 102 intake, headers and true duels and I have yet to get it tuned. I been waiting to gather the final pieces for my heads/cam swap before I get it on the dyno. Sure enough Saturday I had to change my o2 seńsors again because its running really rich burning oil. If that's the case for you swap out your o2 sensors, and if you don't plan on getting anymore mods on your car get a mail order tune. They will tune out your rear sensors/egr and you will see some hp/tq gains from the tune. Bosch 13111(part#) corvette o2 sensors will fit the long tubes. Also check your plugs make sure there not close to fouled out.

Raoul-Duke

iTrader: (6)

Hi, yes I have a mail order tune done with my current mods (Nelson Performance)

I have full bolt ons, also longtubes to true duals.

The rear sensors are tuned out, I just don't know why the front BOTH went out at the same time after I disconnected the rears.

I highly doubt there is an exhaust leak, it sounds great.

flattusmaximus78

iTrader: (1)

Most likely old. Most go bad after long tube swaps. I had long tubes put on and and a diablo handheld to clear codes for the rear. When I put my new engine in the codes came up. Get a scanner. They are probably fine. Sometimes the light comes on and they don't affect fuel trims. Mine didn't. I had the code disabled, but my light wont come off.

Raoul-Duke

iTrader: (6)

The headers weren't changed just the y pipe w exhaust to an x pipe w true duals.

I had the codes read its both front o2 sensors, and it does seem I am running an open loop (rich) because it backfires and pops slightly when shifting over 4k+.

flattusmaximus78

iTrader: (1)

I know you didn't, I was just stating common occurances. You need to list the codes. It could def be an exhaust leak even if you don't hear it.

My cutout was near my old wideband. Probably about a foot away. Cutout didn't leak at all that the ear could hear, but it leaked enough air out to destroy the sensor.

Raoul-Duke

iTrader: (6)

I guess its a possibility. Its a brand new TSP X-pipe dump setup though, unless there could be a leak coming from the head/header?

I'm going to pick up some Denso O2 sensors from Rock Auto in a few weeks and see if that does the trick.

However, I still think its fishy they both went out at the same damn time. bla.

flattusmaximus78

iTrader: (1)

I know, I chased my tail on this forever cause the light bothered me. I replaced them with two denso 02's. Same light and same code. They were switching fine and it doesn't affect anything. At that point when you can confirm that, just have a tuner set it to no report so you don't need to look at the light.

Good luck man, it gets annoying!

Raoul-Duke

iTrader: (6)

Thanks man, I would have a tuner just do it all but Nelson performance locks their tune so no one can access it.

flattusmaximus78

iTrader: (1)

That sucks lol.

1320Chicken

iTrader: (4)

Just a question and I know I'm late to the party here but when you say cut off the rear o2s what do you mean? Turn them off in the computer or physically cut wires? I could be missing something but it reads to me that they were cut. If that's the casein possibly caused the wires to touch and short popping the fuse or the computer swing an electrical fault.

I could be misreading but I'm like you it seems funny that the front o2s take a dump when the rears are messed with, especially since the long tubes were previously installed and tuned.

Raoul-Duke

iTrader: (6)

Yes.

What happened was we were putting on my TSP true duals. I was fitting the X-pipe connectors on the headers while my friend was behind me. He noticed the rear o2 sensors were just zip tied to something, not hooked up, but still plugged in.

He just ended cutting them off and un plugging them without me knowing.

He said I didn't need them, which I knew I didn't but of course now I threw those two friggin rear codes. I had it scanned about 2 weeks after this occurrence and at that time I was only throwing those two rear 02 codes.

Then I had it re scanned about 2 months after that, maybe a total of 200 miles were put on the car. And I was throwing all four, front and rear o2 sensor codes.

What gives? lol

Raoul-Duke

iTrader: (6)

Update:


Drove 30 miles to work.

Left work on my way home 30 miles back, check engine light comes on like I expected. Car is still running 100%.

Stop at autozone to get scanned and it is throwing P0154 & P0155.

Both related to passenger 02 sensor, Driver side is now ok somehow.

Start car up, car will barely even drive. I couldn't get above 2k rpms without losing all power and the car sounding like something I have not ever heard in my entire life.

I am so ******* pissed right now, cannot even get above 40mph. Every gear cannot go above 2k.

I am starting to think it is the tune itself. I don't know why the hell Nelson performance locks their tunes in the first place. Its not like this is some 8 second turbo race car, its a bolt on ls1.

Fed up, sending it into a trusted mechanic tomorrow. May just be the 02 sensors, but after we get that squared away. I'm having Nelson send me a stock UNLOCKED pcm back.