02 sensor help

[DrMilhouse]

I've had engine codes going for a while, but I'm getting ready to do something about it.

I'm getting messages about my bank 1 and 2 sensor 2. Is this the O2 sensor that is on the header?

If not, where are they to replace them?

[2001NBMZ28]

Is the exhaust stock? What are the codes? Sounds like you're saying you're getting codes for just the post cat 02's, and not the precat 02's.

[DrMilhouse]

The muffler is not stock (It's ravin' - I'm not impressed), other than that, the exhaust is stock.

The car runs on e-85 (it was throwing codes way before tuning to e-85)

It has a bigger cam (don't know the specs)
It has ported heads (don't know specs)

It usually throws a p0161 for one of them, I'll go get the codes in a few minutes

It also throws a p300, I'm told that's because a cam could through a random misfire and not to worry too much about it. I know it misfires on cylinder 1 usually, I've replaced plugs, wires and coil pack for that - no change.

[DrMilhouse]

Eh, I just went to get them, I'll post in a minute.

[DrMilhouse]

This is reported by one of the predator tuners.

P0137 - O2S Circuit Bank 1 - Sensor 2 - Low Voltage
P0157 - O2S Circuit Bank 2 - Sensor 2 - Low Voltage
P0161 - O2S Heater Circuit Bank 2 - Sensor 2 - Malfunction
P0172 - Fuel Trim - system too rich
P0175 - Fuel Trim - system too rich
P0300 - random misfire
P1626 - Anti-theft


I knew about the others already, the too rich is new.

All intake is stock except I removed the mesh from the MAF

Again, it runs on e-85 and all the other issues were there long before e-85

(the cam and heads were put in by a hack shop)

[DrMilhouse]

oh, the car has just under 100K on it. The engine some where around 60K

[DrMilhouse]

anyone?

Sorry, I know I look impatient. I'm leaving for vegas for the week on Monday and ordering parts tomorrow so I can leave the car in the shop with my friend who will fix it while I'm out of town.

I appreciate the input.

[0rion]

what's really throwing me is the e85 tune. I'm not sure what's involved in running one of these cars on e85. I'm also not sure if your O2 issues could be from running e85 along with those rich codes. You say you are running cats and these aren't efficiency codes so I'd rule out cats but it could be bad O2's. The rears are the O2's after the cats so they're not the ones in the headers.

[correct1]

Had same problem. check fuel pressure.had same codes on mine and fuel pump was going out.changed fuel pump and dont have them throwing the codes anymore.hope this helps

[DrMilhouse]

what's really throwing me is the e85 tune. I'm not sure what's involved in running one of these cars on e85. I'm also not sure if your O2 issues could be from running e85 along with those rich codes. You say you are running cats and these aren't efficiency codes so I'd rule out cats but it could be bad O2's. The rears are the O2's after the cats so they're not the ones in the headers.

Thanks for the help. Setting up for e-85 wasn't that difficult. I just paid someone to tune the car for e-85. I don't know if there was a HUGE power gain in going to e-85 since it was never properly tuned to begin with. When I did have it tuned, it's as if they woke the car up. It finally performed great.

Let me give other symptoms I deal with and you guys can tell me if it's related or not.

When I first start the car, it drives for shit. Until it's warmed up - like really warmed up - if I floor it, it stalls and dies. If I'm easy on it, it runs okay, but not great. After it's warmed up, it does fine.

I'm finally getting to the point financially where I can keep this car going and even do some upgrades. I'm having my friend to some work to it while I'm gone this week but want more input to make it run right as is before I go dumping more money into other upgrades. I'd rather not spend money on an upgrade when things aren't going to improve because it's not that great to begin with.

Anyone have any suggestions for the misfire on cylinder 1? It's not a compression issue. I don't remember what the compression was when I had it tested, but it was good.

All I'm having done to it this week is struts, new hubs on the front and a rear axel seal replacement.

[Frost]

.....

When I first start the car, it drives for shit. Until it's warmed up - like really warmed up - if I floor it, it stalls and dies. If I'm easy on it, it runs okay, but not great. After it's warmed up, it does fine......

Failing or bad MAF or just not a solid tune on the e85. What you describe above is being rich/lean in open loop; the base tables are incorrect. It's not clear if you will be able to diagnose and fix this without the proper equipment.

[Frost]

P0137 - O2S Circuit Bank 1 - Sensor 2 - Low Voltage
P0157 - O2S Circuit Bank 2 - Sensor 2 - Low Voltage
P0161 - O2S Heater Circuit Bank 2 - Sensor 2 - Malfunction
These and the p0300 should have been fixed when it was tuned as well (unless you have cats still); pretty common fare.

[DrMilhouse]

Thanks man. Yes, I do still have cats.

If the tune, new plugs, new wires, new coil and compression is there, do you have any other thoughts as to why the misfire would keep happening on #1? Would it be related to the failing MAF you mentioned?

[DrMilhouse]

[Frost]

You need to be able to verify whether or not it is real...

[DrMilhouse]

argh... maybe it's because I'm still recovering from Las Vegas... I need to verify whether or not what is real?

[Hi-Po]

argh... maybe it's because I'm still recovering from Las Vegas... I need to verify whether or not what is real?

The mis firing

[DrMilhouse]

02 sensors replaced today finally. The old ones were pretty well baked. Hopefully this will make a difference. The car always runs pretty good when it's warm, but tonight or tomorrow I'll have a chance to go from a cold start and see how it runs.

[0rion]

02 sensors replaced today finally. The old ones were pretty well baked. Hopefully this will make a difference. The car always runs pretty good when it's warm, but tonight or tomorrow I'll have a chance to go from a cold start and see how it runs.

the O2's aren't functioning when it's cold.....they don't kick in until the car goes to closed loop.

[DrMilhouse]

the O2's aren't functioning when it's cold.....they don't kick in until the car goes to closed loop.

So you are saying the o2 sensors will have nothing to do with this running crappy until it's been driven a few blocks?