Swapping with a manual transmission will cause a smog check nightmare.
Your truck will not pass the smog check with a manual transmission unless you replace the engine control computer (and more than likely, the donor engine itself), as well. The current ECU has required inputs from the automatic transmission. When you install the manual transmission, many of these inputs will be missing. With that said and assuming we go ahead and replace both the transmission and ECU from the donor truck, we run into another problem; engine sensor inputs. The ECU from the manual transmission engine might be lacking required sensor/actuator PIDs. Simply swapping out the transmission along with donor ECU will not work, especially on later model vehicles with dozens of sensor inputs and sophisticated drive cycle parameter requirements. Your check engine light will more than likely illuminate and the truck have no chance of passing the inspection.
So is there a way to swap the transmission and still pass smog?
Yes. The best way to handle a swap from automatic transmission to manual is to do a full engine/transmission change. Note, ensure the swap is not degrading engine emissions at all. You do not want to swap with an older model, higher emission producing engine. The BAR will not allow this.
What happens once I'm done with the transmission swap?
Once the work is complete you'll have a State Smog Check Referee inspect your truck to ensure the job was done correctly and your truck passes the smog check with its new engine and transmission. You'll need to contact the smog referee's office at (800) 622-7733 and make an appointment to visit your local referee inspection center.
posted by SmogTips Support
