check engine light

[fish92]

ok so I just got done with an engine swap on my 94 ranger and I have had a check engine light coming on and off since i got it going so I took it to auto zone got the codes and it read that there was a lean fuel mixture and a low running temperature. they tell me the lean fuel mixture could be a vaccum leak but I have looked and there is nothing obvious and i know that there is an exhaust leak both in front and behind the cat but after the O2 sensor. could the lean fuel mixture be caused by the exhaust leak? and start with fixing that or should I start by looking for less obvious vaccum leaks like at the intake manifold? any suggestions?

 

[Duane867]

Fix the leak before the cat 1st.

 

[modelageek]

ok so I just got done with an engine swap on my 94 ranger and I have had a check engine light coming on and off since i got it going so I took it to auto zone got the codes and it read that there was a lean fuel mixture and a low running temperature. they tell me the lean fuel mixture could be a vaccum leak but I have looked and there is nothing obvious and i know that there is an exhaust leak both in front and behind the cat but after the O2 sensor. could the lean fuel mixture be caused by the exhaust leak? and start with fixing that or should I start by looking for less obvious vaccum leaks like at the intake manifold? any suggestions?

what were the actual code #'s a low running temp or a bad ECT sensor can mess things up

 

[fish92]

I dont remember what the numbers were but I do remember when the guy at autozone looked the numbers up in the book that was the exact wording of the codes that I got. but it is OBD1 diagnostics so the codes are pretty vague.