Ok lately my car hasn't been running that well. There is a lack of power, backfires frequently, and the exhaust manifolds glow orange after driving for a while. The car was setting a P0336, even after I replaced the sensor. I did a little research and found that my problems could be due to a bad opti, the car does have 140K on it.
This morning, while on the freeway, the rpm's started to fall, rise, and fall again, like it was struggling to stay alive, backfiring too. I found a place to pull over and it died. I won't start now, just cranks forever. I pulled the codes and I am getting:
P0101 Mass Air Flow System Performance
P0336 Crankshaft Position Sensor Performance
P0400 EGR Flow Malfunction
Can I assume that this is still opti related?

 

If you have an LS1 (your name...)you don't have the Optispark. Your symptoms (while I don't know what P0336 is offhand) sound like a plugged catalytic converter.

 

You need to fix the CKP sensor problem first (P0336)
DIAGNOSTIC AIDS

The following conditions may cause this DTC to set:
[*]Poor connections-[*]The sensor coming in contact with the reluctor wheel[*]The engine running out of fuel[*]Bad sensor[/ul]
Symptoms:
[*]Erratic engine operation[*]No start[*]Start and stall[*]Erratic engine performance [/ul]
For the MAF problem:
You can unplug the electrical connector to the MAF. The engine runs OK without the MAF but will lite the MIL. If it runs good with the MAF unplugged, you may have a MAF problem.

For the EGR problem:
The EGR and gas passages could be dirty or clogged. The EGR and connectors could be bad, or there could be excessive back pressuremessing with the EGR.(plugged cat, as 02StangGT said).

 

Sorry, I thought I had put info for my signiture, ill do that soon. I have both a 99 and a 97 SS. This problem is with my 97. I have replaced the cps sensor and checked the connections already for damage, corrosion, or high voltage lines nearby. Disconnecting my MAF was the first thing I tried, but it still wont start. I disconnected it before aswell, when the car was still running, and had the same symptoms. Also I replaced on of my cats last month, and both exhaust manifolds glow.

 

Glowing exhaust cast iron manifolds is usually caused by bad cam or ignition timing, or bad fuel mixture. Headers are prone to glowing whenever the engine is working hard. The opti may be sick and since it provides timing signals to the PCM it could cause a bunch of problems.

 

Well I ordered an opti and I'm gonna replace it tomorrow. I will post my results when I am done.

 

Well I replaced the opti last night, took a while. The old opti was very corroded and it rattles as if one of the screws backed out. Haven't opened it up yet.
Drove the car for a short while this morning. Feels much better, no backfiring, no stumble, won't know if the manifolds still glow until night. No codes for the short trip yet. Hopefully it stays that way, don't want to get too excited too quickly.[/align]

 

Well, the car seems to run normal again, but the p0336 code is still there. I don't get it.