After I accessed the codes and replaced the coolant temp sensor my blazer became slow to start. (Before it fired right up every time, now it takes a little cranking). When it does start it idles fast then slow then the check engine light comes on and it runs fine but the light stays on. I checked it and it coded 21 meaning TPS voltage low? I have a mind to buy a new sensor as this truck sat for a little while before I bought it. Will this solve the issue? it is only a 50 dollar part. Also I want to clean the MAP Sensor can someone explain how to do this? Maybe the injectors as well? I put seafoam in the tank once already and am thinking about it again to clean out the system.