engine light with rough idle

1998 350 5.7l engine light has been on about the past 6 months.Three weeks ago i had my lower intake gasket replaced. After i got it back i changed the egr valve which was my problem code from before. I got it scanned again and the code p1345 (new code, egr code was gone) came up. I was told the timing was off so i took it back to the mechanic who then said i had slack in my chain after trying to retime it and suggested to replace it. Now after replacing the timing chain and gears i still have the p1345 code and now there is a p0300 code and it still has a rough idle. Also the spark plugs have been changed because of the rough idle but no change. Any help please.

1345 is the cam and crank sensor not synchronized, the dist needs to be moved up or down somewhat to set the cam to crank sensor correlation, this must be done with a highline scanner, this also assumes the chain and gears are timed correctly also.

Ok You say a highline scanner so i quess i wll need to go to a good auto shop to get this done or do these sell for a reasonable price?

Is the highline scanner also refered to as a timing light?

Is the highline scanner also refered to as a timing light?

No. You need a scanner that can read Cam Retard to set the timing on a Vortec engine.

//2000CAYukon

ok thanks. Also i was told that the code scanners autozone uses and the highprice ones alot of the the big shops use are the same then someone else told me that they are different whereas the high price scanners are able to grab the code, and pinpoint exactly whats wrong.
ex: p0300 says mutltiple missfire and the scanner will say plugs 2.5, and 6. Which has more truth to it? thanks to all for the help

Over simplification, the pro scanners have built in troubleshooters, can access live info, can command certain functions, can check cylinder balance and so on, AZ is basically just a code reader.

I was just wondering if you had your problem figured out? I seem to be having the same problem with a 96 5.7 vortec.

Welcome AF, this thread is too old, start a new one, thanks.