Running rich?

[426allmotor]

Ok so here is my problem. I have a 2000 neon that I hollowed out the exhaust manifold, and cat because the material inside broke down and clogged up. I have an intake and high flow muffler. Before I put on the exhaust, The car threw a CEL for the o2 sensor. I cleared the code once and it ran great, but it came back a day later and now the car is running pig rich. Along with my gas mileage that is now in the crapper. Is there a way to get rid of the CEL and stop making the car run rich? I though there was a way to fool the o2 sensor? Any help is appreciated, thanks.

[white2000neon]

Your upstream o2 controls your target a/f so that is what is probally making you rich replace that and the car should also throw a catalyst inefficency code for having a hollowed out cat. Look up the how to trick your comp for no cat.

[dansou5]

How can you tell that you are running rich?

But anyways this is what you should follow. This should work on the non R/T motors. Make sure that you use two of the plugs/
http://forum.2gn.org/viewtopic.php?t=1025

[neon angel]

i threw a similiar code p0131 low 02 voltage dose this mean the up stream o2 and im running rich or lean?

[426allmotor]

The thing black smokes like a diesel, thats how I know it's running rich. Just to clarifiy the one in manifold needs replacing, and then use the non-fouler on the second sensor? Do I just use one, or both? Thanks guys I'll let you know.

[dansou5]

^^ yea thats right about the sensors. I always thought smoke is from running lean.

How many miles are on the engine?

[white2000neon]

nope black smoke is running rich.

[occasional demons]

Your upstream O2 is prolly damaged if both of your cats were melted. It is likely the cause of their demise: if it is running rich it will melt the platnum bricks. Or if something contaminated the cats, say coolant for example that will also destroy an o2 sensor. The only other cause would be the FPR not limiting pressure. Check the code that is there for the o2. It should specify which o2 it is for and if there is a rich or lean condition or fauty sensor just a matter of deciphering the language.
P0130 1/1 02 Sensor Heater Relay Malfunction
P0131(M) 1/1 02 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal operating range
P0141 1/1 02 Sensor Relay Oxygen sensor relay bad
P0147 1/3 02 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0151(M) 2/1 02 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal operating range
P0152(M) 2/1 02 Sensor Shorted To Voltage Oxygen sensor input voltage sustained above normal operating range
P0153(M) 2/1 02 Sensor Slow Response Oxygen sensor response slower than minimum required switching frequency
P0154(M) 2/1 02 Sensor Stays at Center Neither rich or lean condition is detected from the oxygen sensor
P0155(M) 2/1 02 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0157(M) 2/2 02 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal operating range
P0158(M) 2/2 02 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal operating range
P0159 2/2 02 Sensor Slow Response Oxygen sensor response slower than minimum required switching frequency
P0160(M) 2/2 02 Sensor Stays at Center Neither rich nor lean condition is detected from the oxygen sensor.
P0161(M) 2/2 02 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0171(M) 1/1 Fuel System Lean A lean air/fuel mixture has been indicated by an abnormally rich correction factor.
P0172(M) 1/1 Fuel System Rich A rich air/fuel mixture has been indicated by an abnormally lean correction factor.
P0174(M) 211 Fuel System Lean A lean air/fuel mixture has been indicated by an abnormally rich correction factor.
P0175(M) 211 Fuel System Rich A rich air/fuel mixture has been indicated by an abnormally lean correction factor.

2/1=upstream
2/2=downstream IIRC.