Quote:
Originally Posted by madrieger
After driving on the freeway for a while (15 min+), when I slow down the service engine light comes on and the truck runs rough. When I try to stop, I dont have much for braking power. Sometimes it goes away and runs fine.
I just changed the MAP sensor and it is running rough all the time.
Is there anything else for code 33?
Any other ideas? 
I also changed the alternator because the gage said about 11 volts, now it says 15.
Thanks |
First thing a code does not say replace part.
In good repair information.
There is repair flow charts for codes.
With a code 33 check for good engine vacuum to map sensor and the wiring from map to computer.
Check you map sensor voltage voltage reading.
What is reading key on engine off and engine idle and and engine under load readings?
You may also have a egr valve sticking open causing map sensor reading to go to pot and rough idle.
With low engine cacumn and lose of breaking power.
Check your engine vacuum and see if it is dropping when it acts up.