can the stock 1994 ecm be tuned or is it factory fixed? changed the right side o2 sensor yesterday hoping that was making the right side run rich and stop the loud popping but it did not when I took the car for a test ride after the car seemed to run hotter on the temp gauge dont know if o2 sesor made a difference. I put the new stock sensor back in, the car has headers sensor went in at the collector area. I dont have cats but have some on order but if the right side is running way rich I dont think the cat would last very long from previous posts the cat could take care of the popping [gunshot loud] but am trying to figure out the running rich problem first, pulled the plugs on the right side they all looked good and the same color. Car runs great no missing or stumbling when driving Also checked engine codes a 12 came up but nothing else. Any ideas install the cats hope it doesnt burn out can anything be gained by going to a shop that can read the OBD1 would it show what is going on?
1994 engine control module
- Thread starter whatthe
- Start date
99 R/T 10
Enthusiast
If your PCM wnet bad, you will need another one. The only whay to properly tune a Gen I is to get a Roe Vec 2/3. I don't believe a SCT can be used on a Gen I.
maybe get a HP cat?
maybe get a HP cat?
RoyV101621
Enthusiast
Call Dan Cragin tech and ECU extraordinare
vprtech
Enthusiast
Question for you, did you recently have the intake manifold off the engine. I have seen an issue, where two or more injector connectors are swapped left to right bank, which causes the fuel trims to ramp all the way rich or lean. What you really need to do is get the car hooked up to a scan tool. Your best option would be to look out for a used DRBII on EBAY (make sure it has the six way cable and the supercard) or to get the pc based scan tool software from EASE DIAGNOSTICS. If cost is a concern, I believe ease has some older versions of their tools that they are willing to sell on for a considerably discounted price. The ecu can be reprogrammed, that is what I did for DC Performance, and although I don't suggest it, the ecu can be calibrated to run in open loop all the time and ignore the O2 sensors.
DJ'sviper
Enthusiast
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I just had headers and exhaust put on my Gen I 93. It sounds great but sometimes when I cost off the accelerator it backfires (like a gunshot loud). I thought since their wasn't any resistence throught he exhast that was the issue. With your post it seems that their is more to this. Can this hurt the engine?
somebody with more knowledge might wqnt to chime in on the possible damage to engine but I dont think so once I got rid of the resonater and put on a Roe hi flow cat and magnaflows the gunshot loud pop turned into a popcorn fart loud noise very much of a improvement I plan on doing nothing about the cause of the noise
vprtech
Enthusiast
Popping or backfiring through the exhaust can be made much worse by leaks in the exhaust system. If there are leaks the extra air is siphoned in and helps to combust unburnt fuel in the exhaust on deceleration. The ecu can be reprogrammed to cut all fuel when the throttle is released which would prevent any exhaust pop on decel. This can also be done with a VEC2/3.
