My car hasnt been running right for a while, recently change the spark plugs, cleared all codes replacing maf, tps sensors and adjusted timing and still not running correctly, i was looking around to see if anything was out of place/not connected and i came across a wire that was hangning down, turns out its the negative battery terminal cable, there is a thinner wire coming off of the larger one that is grounded to the body (see picture) I believe that the main cable should mount to the engine block, is that correct and if so where on the block does it bolt to as i have no idea, a picture of someones attached would help greatly. Anyway is not having this cable connected the cause of the poor running of my car?

 

the negative of the battery has a small wire which goes to the body and the thick wire connects to the engine. If you have aluminum heads then it can't be connected to the heads or exh manifold.

If you have iron heads and stock exh manifold then bolt it to the exh manifold.

If you have headers, find a bolt on the block where you can attach it

 

While you are checking your grounds, make sure you have a good ground strap from the engine block to the body as well. They are usually off the back of the head to the firewall. But again, if the heads were swapped to aluminum, your going to have to find an alternative bolt.

if the whole car is grounded off that small wire to the frame, they could absolutely cause sensor and ecm issues.

 

Thanks, i do have iron heads and stock manifolds, also have header so i will bolt it up to one of those bolts, thanks. Hopefully that clears up my issue.