Hello everyone:
I just picked up a 33,000 mile 2003 GT, 4.6 liter. The only mod that I can see is Roush side exhaust. The only thing I have done so far is to add a K & N and remove the air silencer. (Really woke up the exhaust!) Here are my questions:
Yesterday driving on a relatively steep grade the car started pinging bad. I was in 5th at about 75 - 80. Even downshifint to 4th the car was still pinging. Should I do a tune up now (should be plugs only I think)? or is there something else that I am missing? There are no codes and other than this the car has run fine.
What can I expect for intervals on the tune up?
Is the cause of this the crappy gas in California and if so should I run 89 or 92 octane? (Is there a better brand than Chevron?)
Sorry for all of the questions, but I have an 800 mile road trip next week and want to make sure the car is in great shape.
Thanks in advance for your help,
Matt
I just picked up a 33,000 mile 2003 GT, 4.6 liter. The only mod that I can see is Roush side exhaust. The only thing I have done so far is to add a K & N and remove the air silencer. (Really woke up the exhaust!) Here are my questions:
Yesterday driving on a relatively steep grade the car started pinging bad. I was in 5th at about 75 - 80. Even downshifint to 4th the car was still pinging. Should I do a tune up now (should be plugs only I think)? or is there something else that I am missing? There are no codes and other than this the car has run fine.
What can I expect for intervals on the tune up?
Is the cause of this the crappy gas in California and if so should I run 89 or 92 octane? (Is there a better brand than Chevron?)
Sorry for all of the questions, but I have an 800 mile road trip next week and want to make sure the car is in great shape.
Thanks in advance for your help,
Matt

. I am just woried about doing the Plugs because of the horror stories about plugs blowing out! I don't want that!