lag/sputter on accelereation and horrible gas mileage

[putang29]

So when I accelerate, my car always has a lot of lag. I hear a lot of head chatter too mainly from the passenger side heads (same area has lifter tick). Usually around 3k to 4k after the car is to operating temp, it picks itself up and seems to accelerate the way it should. Any advice on troubleshooting this?
Car gets s*** gas mileage too. Like 3 days and 1/2 almost is gone and it smells like it is running very rich...I get no codes and no check engine light is on.

ps i am planning on buying TT heads to replace my na ones they do not have any tick and were in good running condition beofre being pulled. is this a good idea for 135 for them? thanks.

[robomatic12]

What's the mileage? When was your most recent maintenance and tune-up (spark plugs, fuel filter, air filter)?

[putang29]

doing timing belt n pulleys this weekend, did air filter last weekend, fuel filter was done maybe 500 miles ago. had 2 oil changes within 1k miles + lucas , runs royal purple 5w30 for now. Cleaned throttle bodies w/ cleaner spray a toothbrush n rags. Spark plugs idk, I will probably do them this weekend after the timing is finished.

car has about 154k on it...

[robomatic12]

Search on how to test the o2 sensors with the ECU. They are probably getting lazy and causing the car to run richer.

Do you still have your EGR? Any deletes been done on the Z?

[cbedessie411]

Probably injectors,spark plugs,maybe sensors....

[es.biggs]

I always tell everyone, wouldn't hurt to check the ignition timing. Very simple, takes 5 minutes!