I have a 2002 saturn sl1 4cyl. 109 engine it has a miss on no.1 cylinder .?

Hi so even when you have replaced all the electrical components it still misses i bet you have missed something out it looked alright so it was put back in and it is the cause of the problem a HT lead is one of those things and also have you done a compression check a burnt valve can also be the reason.

Saturn. Proper name of a brand of automobiles. SL1. Specific model of Saturn. Also needs larger letters. Any answers you ask? Well, the social and psychological and cultural trends you cataloged in your statement are common and are a testimony to what could possible be construed as not doing the right thing when there are mechanical issues with vehicles. the common trend for young people like you who perceive auto mechanics as thieves waiting to steal your money is to attempt to repair their cars without knowledge, training nor experienced by the traditional guessing alternative using the "It has to be the_____" method. That explains the new coils, wires and spark plugs. All wasted money and effort. So, while the most common and correct answer is to seek professional help in automotive issues is not on your radar screen, the only other possible suggestion is to get you to sign up for mechanic school. About a year's worth of school, testing, practical shop classes, etc. Lots and lots and lots to learn. Once you become ASE certified and have the tools and equipment you can then perhaps properly repair this Saturn SL1 as to the idle issue with number 1 cylinder. Or you can find a mechanic or you can buy a different engine or a different car. Alternatives to be considered based on cost and time. So, what is your decision? Cars are very complex machines. It takes an expert to deal with these problems and even then, the intelligence, the dedication, the ability to solve problems varies from mechanic to mechanic. The answer I have provided is based on decades of experience and it is the best I can think of as to your specific situation. As to the English grammar issue, well, same thing applies. If you learned English at school, why not use that knowledge to write correctly? Discipline? Peer pressure? Lazy? More convenient? The significance of the implications as the cultural issues this represents can take pages of discussion. Not enough space here. Sorry, but I have to close as I have to prepare for a seminar on the possible consequences of our school system failing to provide the most basic of skills to our students. Best of luck with the vehicle.

Have you tried swapping positions on the fuel injectors? (which engine ver.)

Compression test? Close match cyl. to cyl.?

Ignition module?

see

maybe you have a valve not seating right !