88 4runner 22re. I replace the head, head gasket, timing change fuel pressure regulator in my runner. Over heated due to a cracked head. It idles fine and will rev up fine. It's very random that every now and then I get what sounds like a knock or back fire by the cat converter. I also have no power under load. Step on gas drive and it bogs down. Need to get this back on the road soon. Any ideas what might need to be adjusted of fixed? After I let it idle a for a few minutes and go to start 20 minutes later it will only start if I spray starting fluid in the throttle body.

 

Restricted exhaust system? Via the catalytic converter.

If you have a vacuum gauge you can find out real quick if the exhaust is resticted.

Normal engine vacuum is about 18-22hg on the vacuum gauge.

If upon opening the throttle the vacuum drops more than 10hg and near to zero the exhaust is restricted.

 

Kiroshu you were right. Vacuum showed clogged Cat. Replace and now it's running good. Thanks

 

Np. Glad to help ^_^