The first component we'd suggest looking into would be your Toyota Pickup's EGR system. The EGR valve is the number one component used for NOx reduction. Second would be fuel control (oxygen sensor). If you have the engine running lean your going to come across high NOx issues.
We'd recommend ensuring the EGR system works, the EGR passages are free and clear of any carbon build-up. Second make sure your Toyota Pickup Truck is in proper fuel control. This means the oxygen sensor is sending the correct signals to the ECU and the ECU is commanding the proper amount of fuel to the combustion chambers.
posted by SmogTips Support
