I recently had my cylinder head replaced. At first i had no cel. After about a 100 miles it came on. I pulled the code i got a 12 and a 25. I think the 12 is normal because when the head was replaced power was disconnected. Anyways i pulled the code and it was a 25 i turned the code off it stayed off for about 2 days. I than was told by the person who changed the head that the vacuum line off the tb may be bad i replaced that and reset the code. It came on right away on the next start. The car still runs great and i don't notice any difference in the idle but the dang light is on for a reason and would appreciate any help i can get. Thanks in advance.

 

theres other vacuum hoses that could cause it... i replaced every single one until i finally came across that it must be the brake booster...surely enough it was broken replaced it and fixed the idle problem...didn't fix the brake problem though...

Hows that big hose that goes from the brake booster to in front of TB?

 

my battery terminals are messed up and i replacing those today. Do you think that could have caused the problem? That's why code 12 is on. do you think it could have lost voltage and threw that check engine light when it starts?