why did my check engine light come on after I had my spark plugs changed and added gas treatment


Asked by Jul 08, 2015 at 10:31 AM about the 1999 Mercedes-Benz M-Class ML320

Question type: Maintenance & Repair

1999 ML320 170K - car will only start after 2nd try when turning the key, now check
engine light is on after tune-up- the car is not running hot but slow.

5 Answers


WHY put gas treatment in??!!!!


because the car was not turning over the 1st time I tried starting the car so my mechanic said put gas treatment- I only use 93 supreme


The mechanic had just finished putting my spark plugs in that day

Tom Demyan

Check your gas cap, see if it's tight. If the light doesn't go off after 3-4 cycles, then have the car scanner for the codes.

Best Answer
Wade Frazier

Go to AutoZone and have them scan for the code for free and see what the cause is... Then you willl have a good starting point... It could be a number of things going on with your car...

Your Answer

Add photo

Related Questions


Looking for a Used M-Class in your area?

CarGurus has 6,077 nationwide M-Class listings starting at $2,950.


Search Mercedes-Benz M-Class Questions

Mercedes-Benz M-Class Experts

#1 jihadghazali
Reputation 1,030
#2 wellness
Reputation 780
#3 stardust
Reputation 510
View All

Related Models For Sale

Used BMW X5"
551 Great Deals out of 15,503 listings starting at $1,995
Used Mercedes-Benz E-Class"
791 Great Deals out of 22,747 listings starting at $1,850
Used Mercedes-Benz C-Class"
871 Great Deals out of 32,027 listings starting at $1,900
Used Mercedes-Benz S-Class"
182 Great Deals out of 6,628 listings starting at $2,900
Used Mercedes-Benz G-Class"
21 Great Deals out of 815 listings starting at $22,884
Used Jeep Grand Cherokee"
1,158 Great Deals out of 73,680 listings starting at $1,500

Used Cars For Sale

2015 Mercedes-Benz M-Class For Sale
26 Great Deals out of 638 listings starting at $31,500
2014 Mercedes-Benz M-Class For Sale
71 Great Deals out of 1,391 listings starting at $24,977
2013 Mercedes-Benz M-Class For Sale
45 Great Deals out of 537 listings starting at $23,900
2012 Mercedes-Benz M-Class For Sale
40 Great Deals out of 466 listings starting at $17,709
2011 Mercedes-Benz M-Class For Sale
25 Great Deals out of 459 listings starting at $12,900