Code 41 - EST Circuit (Electronic Spark Timing) or CMP Sensor, No distributor Reference pulses to the PCM at specified engine Vacuum, A malfunctioning ignition module can very easily cause this code to set. If the EST circuit is either open or grounded it may very well cause the same problem. Hope this helps.
i have a code 12 on my chevy astro van what it means
Ckp sencer
I have the same van and had the same problem. The error code PO128 is an error code letting you know you need to specifically replace the Coolant Temperature Sensor. The Sensor is about $14.00- $15.00. Just a little work, not bad. I did it and actually helped my gas mileage also. I would recommend Advanced Auto Parts.
Trouble code P0102 means:Mass or volume circuit low input
Oxygen sensor stuck lean.
Trouble code P0172 means:System too rich (Bank 1)
Trouble code P0175 means:System too rich (Bank 2)
it a transmission slipping code
Trouble code P0700 means:Transmission control system malfunction
Trouble code P0101 means:Mass or volume circuit range performance problem
Trouble code P0122 means:Throttle/pedal position sensor/switch A circuit low input
http://chevythunder.com/199295_lt1_trouble_codes.htm