Failed Emissions

[daejuanj]

I had this problem before, thought it was fixed but turns out either a dealership screwed around with my MIL control or it's defective, either way it doesn't turn on.

I had a inspection done. Everything passed but the emissions part.

P0137 Bank 1 Sensor 2
P0420 Catalyst System Efficeincy Below thresshold Bank 1
P0650 MIL Control Circuit
P1133 Manufacturer Controlled Fuel&Air Metering
P1441 Manufacturer Controlled Aux. Emissions Controls

I have a Magnaflow Cat and straigt pipe, and Ubend delete

No noticeable problems

Local shop said they won't touch it due to the manufacturer codes, dealer said to try replacing the cat before I spend $80 for full diagnosis.

Looking for opinions from people familar with my car model

[CrazyHorst]

My MY-2000 W-car manuals state that the P1133 is a HO2S Insufficient Switching Sensor 1. In other words the PCM is looking at the Heated O2 sensor to see if it is switching/toggling. In 100 seconds if less than 40 rich/lean cycles are counted, the code sets.

My manuals also state that P1441 is Evap System Flow During Non-Purge. The vent valve also monitors tank pressure, it thinks the fuel tank pressure is less than -11 inches of water column. An easy problem is that the purge and vacuum lines are switched at the cannister purge valve. Other possibilities are the purge valve is stuck open or the circuit is grounded.

Other than the purge problem it sounds like the post-cat O2 sensor is bad or disconnected...if not the catalyst isn't doing jack. I'd fix that problem first, reset the codes and see what comes back. It is also possible that the pre-cat O2 sensor is bad....or the EVAP vacuum leak is holding the signal low too.

[daejuanj]

Thanks a lot.

Would a o2 simulator work, or should I try and fix the problems?

I thought about replacing the cat, but which one should I buy. I have a Magnaflow 53000 series now.

[CrazyHorst]

I think since you are actually using a catalyst, I'd climb under there with a 22mm or 7/8" OE wrench and screw out the O2 sensor and put in a new one.

If you don't care about that the simulator would probably take care of it since it simulates "good" electrical action.

I wouldn't monkey with the cat until you fix the other problems.

[daejuanj]

Originally Posted by CrazyHorst

I think since you are actually using a catalyst, I'd climb under there with a 22mm or 7/8" OE wrench and screw out the O2 sensor and put in a new one.

If you don't care about that the simulator would probably take care of it since it simulates "good" electrical action.

I wouldn't monkey with the cat until you fix the other problems.

how should I fix the other problems?

[CrazyHorst]

Check the MIL fuse first. Everything after that involves getting into the cluster/instrument panel or replacing the PCM.

[daejuanj]

Originally Posted by CrazyHorst

Check the MIL fuse first. Everything after that involves getting into the cluster/instrument panel or replacing the PCM.

Gotcha is there a fuze diagram somewhere on this site?

[danielsatur]

The upstream HO2 sensors are needed, they are used for feed back for the Air/Fuel mix, the downstream HO2 sensors tell the ECU/PCM, if the catalytic converters are working.
O2 simulators are used down stream to lie to the ECU/PCM about the catalyst.

[daejuanj]

Originally Posted by danielsatur

The upstream HO2 sensors are needed, they are used for feed back for the Air/Fuel mix, the downstream HO2 sensors tell the ECU/PCM, if the catalytic converters are working.
O2 simulators are used down stream to lie to the ECU/PCM about the catalyst.

Im gonna get the cat fixed and see what happens afterwards

[CrazyHorst]

That's cool and all but that logic defies common sense in my book. The cat converter is the highest-priced and least-DIY project unless you "flanged" it and the OE unit is similarly flanged to swap back in.

The O2 sensor(s) are readily available and easy to change yourself. If that is not the correct answer you then have a known good spare.

I don't know what you pay for a new cat to be purchased and installed (guessing $500 for someone else to do the work). In my book that's worth a stab at a new O2 sensor (guessing less than $100) with your 7/8" box end wrench. OR...an O2 simulator is less than $50 puchased and installs with a pocket screwdriver if your thumb isn't tough enough and is basically guaranteed to make the catalyst-related codes go away since it simulates "proper measurement" of the catalyst action. Insert your own "cost figures" to make your own decision. I might be crazy but I am trying to look out for your wallet.

[daejuanj]

Originally Posted by CrazyHorst

That's cool and all but that logic defies common sense in my book. The cat converter is the highest-priced and least-DIY project unless you "flanged" it and the OE unit is similarly flanged to swap back in.

The O2 sensor(s) are readily available and easy to change yourself. If that is not the correct answer you then have a known good spare.

I don't know what you pay for a new cat to be purchased and installed (guessing $500 for someone else to do the work). In my book that's worth a stab at a new O2 sensor (guessing less than $100) with your 7/8" box end wrench. OR...an O2 simulator is less than $50 puchased and installs with a pocket screwdriver if your thumb isn't tough enough and is basically guaranteed to make the catalyst-related codes go away since it simulates "proper measurement" of the catalyst action. Insert your own "cost figures" to make your own decision.

By getting the cat fixed, I mean either the o2 or actually cat. The cat cost $90 and $150 to install btw.

[BNaylor]

Getting a P0420 DTC is common with Magnaflow hi-flo CATs and exhaust system mods. I had the same issue with my GTP a few years ago with my Magnaflow hi-flo (2.5" in/out) and headers. At first I installed a 02 simulator but then had the PCM module programmed to inhibit any and all post CAT 02 sensor DTCs. The PCM is an Intense. No problem passing Texas emissions testing either.

$90 is too much for a Magnaflow hi-flo CAT converter. They were going on EBay for around $55.

Incidently, the 02 simulator came in handy later on and we now use it on our '02 Olds Alero GL2 which also has a Magnaflow hi-flo CAT converter, headers and a Pacesetter CATBack exhaust system.

Also, $150 for labor to install the converter is too much but that may be the going cost in your area.