Fixed exhaust bolt, now the car is running rough

[Razorbak]

The last owner of this car broke off an exhaust manifold bolt, so I removed the manifold and cats and got removed the broken bolt. Reassembled and now the car is running like crap! All I took off were the o-2 sensors, spark plug wires, and the coolant temp sensor, what could I have possibly done to this thing??? I have double checked the plug wires, everything is reconnected the way I found it, I’m at a loss…

[JB'sZL1]

O2 sensors, connections or wiring.

[Razorbak]

Thanks. I hadn’t done this before, and didn’t realize there was no slack in the upstream O2 sensor wire, so the manifold was hanging by the wire for a little bit, I guess that probably damaged it, didn’t know they were so fragile. Thanks for the idea

[silversleeper]

get a scanner if you dont have one, they are cheap. look at O2 and see if its going up and down and if there is a code. then put in all new spark plugs carefully. i think its one or the other probably.

[Razorbak]

Originally Posted by silversleeper

get a scanner if you dont have one, they are cheap. look at O2 and see if its going up and down and if there is a code. then put in all new spark plugs carefully. i think its one or the other probably.

I have a scanner, no codes being thrown, no check engine light. Guess I’ll buy plugs and an O2 sensor and just replace everything. Thanks for the advice!

[ZMEnow]

Originally Posted by Razorbak

The last owner of this car broke off an exhaust manifold bolt, so I removed the manifold and cats and got removed the broken bolt. Reassembled and now the car is running like crap! All I took off were the o-2 sensors, spark plug wires, and the coolant temp sensor, what could I have possibly done to this thing??? I have double checked the plug wires, everything is reconnected the way I found it, I’m at a loss…

Could have cracked a plug when removing or reinstalling the manifold especially if it was the right side..

[silversleeper]

Originally Posted by Razorbak

I have a scanner, no codes being thrown, no check engine light. Guess I’ll buy plugs and an O2 sensor and just replace everything. Thanks for the advice!

Just don't get AC delco plugs from Amazon or Ebay, they sell fake ones that melt on the first drive. Then you are really dumbfounded unless you pull them and realize it.

[Razorbak]

Thanks for the advice to all, found the back spark plug was cracked, manifold must have dropped down on it when I was under the car, sure couldn’t see it when inspecting from the top. Bought new plugs from OReilly going in tomorrow, it was time anyway. Thanks!

[ZMEnow]

Originally Posted by Razorbak

Thanks for the advice to all, found the back spark plug was cracked, manifold must have dropped down on it when I was under the car, sure couldn’t see it when inspecting from the top. Bought new plugs from OReilly going in tomorrow, it was time anyway. Thanks!

99% of the time when someone changes a header or manifolds in this engine they break a plug if they don’t remove them first, especially if it’s the right side.