Ive posted before but for some reason still can't get this figured out.....

To answer your question, yes, I've searched and searched and searched.


2003 Gs300
130k miles
Original everything except for a resonator delete to a couple magna flow mufflers.
Intake

So while i was cleaning my MAF sensor a while ago, i forgot to pull the negative cable from the battery. Immediately got codes for Bank 2 sensor 1, and a code for the CAT itself. tried resetting things, retrace steps, checked wires. Still the same check engine light and VSC lights.

I replaced the o2 sensor closest to the fire wall, which i assumed was bank 2 sensor 1. looked up the part numbers and got a denso o2 sensor. screwed right in, same 4 wire as the other one, yet the plug didn't really seat in. but i figured it was making contact so it should work. Drove the car around for about 10 mins and the lights came back on.

Now I'm reading p0037 and p0154

Im guessing the 37 code (saying no activity from the o2 sensor) is the bad connection? can i just cut the old clip and splice it onto the new o2 sensor? should i swap around the two engine bay 02 sensors and see what happens? As far as the o2 below the passenger seat, thats just a single wire that is the heater o2? I'm lost. help this poor sheep.

I can't figure out what the hell to do now. if anyone has any clear advice or experience please chime in. i will keep researching on this but I'm hoping someone has had similar experience and can shoot me in the right direction. thank you CL members!

 

There is a huge hesitation on initial take off up until 3500 rpm as well, and I'm pretty sure its running rich at the moment too. just FYI

 

There's tons of o2 info on here...but def remove the sensor that doesn't clip in and verify what it is

 

Just my $0.02:

A scan tool that reads out real-time O2 voltages is invaluable IMO. R&R'ing O2 sensors gets old.....

 

Yes, the O2 sensor nearest the firewall is bank 2 sensor 1. The sensor under the passenger seat is bank 2 sensor 2. You can see the equivalence for the bank 1 sensors.

If the new plug is not an exact fit, then certainly, cut and re-use the old plug. Solder the wires and insulate with heat shrink or use a butt splice with suitable crimping tool.

Keep us posted.

 

Dude.... You probably indeed do have a clogged cat.... I've turned headers on a old build of mine CHERRY RED from a clogged cat. A car that was pushing just about 470rwhp I could not get to go over 30 mph. Pulled over popped the hood, I have photo's of my buddy lighting his dam cigerette off one of the headers... Do your self a favor, drill a pin hole before the cat, and another after the cat, compare the pressures of exhaust blowing through. That'll tell you for sure. A cats worst enemy is...... : condensation. Water.

 

Sounds like a motor trying as hard as it can to breathe to me! Very well could be my man. To be honest it would be something first on my check list to diagnose now that you've already done all that you have and now hear this... Or just drop your exhaust and take it for a spin around the good old nascar speed way derby block of yours lol

 

This also happened to me while cleaning my maf. Sensor.
It would give me the same codes,
i dont know how i did it but while cleaning the maf. Sensor
i shorted it out., this is what i was told by my shop.
I had to get a new maf sensor from the dealer and it was fixed

 

So update. I put the new o2 sensor in, cleared the codes, and they came back again. So i put the original one back in, and started chasing some wires, tugged a little on the o2 connector to the engine, and a wire popped out without any effort. Mother F'er! Got it set back in with some environmental splices and what not that i had from the military days, cleared the codes, and boom. Never came back. So damn simple. I can't believe i missed it haha. Anyone need an o2 sensor? i paid 67$ shipped. Pick up for $55 or ship for $60

On a side note, it still is hesitating up until 3500k rmp. So i will start with the normal items for a healthy breathing engine. But if anyone has any pointers I'm all ears. Thanks fellas.



Completely agree. I just have a cheap *** one. I need to invest in a really nice one.

I feel like the cat is toast, but I'm not getting any codes anymore, but the car smells like its running rich, and the exhaust tips are pretty black. I already cut the resonators out and just finished smog. Might just pop the cat out under the passenger side and see how it runs after that.

I agree. Do you think the culprit could be a chinese mesh filter i put in the car? Im about 5 seconds away from just putting another paper filter in. If I'm going to mod the engine i feel like straight to turbo is the only way to gain real power. But i kinda don't care right now. Im sitting pretty low, and i have a modded street bike that make you feel like a ***** when you twist the throttle. so my speed thrill is there haha.

Really? crazy. I know the MAF sensors are sensitive to certain chemicals on them. I just used a cotton swab and rubbing alcohol.

 

I figured out that it was from when i was cleaning my throttle body. I was pulling too much on it trying to get it out of the way and clean everything. I must have not seen that connector still connected and pulled it a little too hard.

 

So is your car back to normal?

 

As far as the o2 and passing smog yes. But i just took off my valve covers and about to swap the sparks, oil, and valve cover gaskets. I've noticed oil has soaked my spark plugs. I'm hoping this is the culprit for my car being so sluggish. I'm going to test the TPS and take a look at the MAF as well.