How is everyone doing, 2 days ago me and my boy where racing around,(he has a 98 Mustang GT Convert) and after the night was over i had this loud Ticking noise like 2 metel peices slaping togeather. So i pulled off my valve cover and found nothing wrong or loose. SO i have no clue whats wrong. It sounds like its coming from my head but who know. I know thats not alot to go on to also it gets really loud at 3000rpm thats when its the loudest. at idle you cant hear anything abnormal. Also i have a cel. I have a test pipe did the resistor mod and i still got a cell but i also have more then one code. So hopefully one of the codes can help me with my problem. i have a code 12,21,55. I left my chiltons manual at RI, when i moved to my next Airforce Base. If anyone can help it would be much aprecaited

if the ticking sounds like its coming from the head area, it could be a bad lifter, or a bent valve...more than likely its a bad lifter if you havent noticed any performance changes.

12 - Normal Starting Code (battery disconnected within 50 key cycles)
21 - O2 Sensor (Upstream)
55 - Norman Ending Code

So you really have that one trouble code 21.
Did you put the resistor in the upper or lower O2 sensor?

As for the ticking noise,
Like ^he^ said, most likely lifter noise... It's pretty common

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=8

No the resistor is in the lower 02 sensor, car idles fine. I just put a new o2 sensor in the upstream when i changed over to 4-1 hearders.

To the other questions. No the car pulls just as hard. I got the noise half way threw the night of racing. Me and my friends last race with a Civic SI. The car pulled just as hard as it did in the beginning of the night.

Check the level of your oil. My car will do that after running hard for a spell. I am burning it off through valve seals and/or rings wearing out. Seems to be a common issue wiht the 420 after a certain mileage range imo.
Also I have a service manual for the 97 Avenger/Sebring, so if you need something just ask.

thanks for the help you are right. i after racing that night my car was 2 1/2 Qts. low. Yea that sucked so i was planing on rebuilding my head anyways but now i get to do it sooner LOL. Also i found my manual after searching for 2 hrs. But the other code i got was for the Rear 02 which i expected. Thanks for everyones help

Glad to be of help! Is it still ticking and clicking? If not you have some time Maybe get a solid base head at a yard and rebuild it so your car isn't down, IF that is even an issue for ya. Also, I noticed you have a B&M short shifter. PM me about how you like it? (No need to take up space on the board) Been looking at those and wondered how someone using it likes it

Carl

well i have to reply anyway. yes its still ticking but its on again off again. I was planing on buying a head and with in the next mounth or 2 and start working on it and getting it ported and the hole nine yards.
The shifter is Great. I love it. Its solid and short as hell. Please with the Symbroski shifter kit. Its a great combo