@Derby52: Fixing the air filter cover with screws is NOT at all is solution, after once or twice after those backfiring the cover of filter will just break and you will have all sorts of problems from extremely back pick/missing and whats not.
@Usmangh: In your case, first step is to change spark plugs, then plug wires, as both of them have been done, the issue is now with coils. As your car kept running on the short plug wires, your coils would have been damaged. Even further there are parts which must be checked.
Along with lots of others, I had same issue with my Santro, fortunately that gone away with just changing the plugs and plug wires for now. And from 2 to 3 weeks it seems to be running very good.
A month before i was much woried from my Santro, but guys here suggested me CNG mechanic who turned out very good knowing person.
Tariq Nawaz Khatak,
I&T center islamabad,
behind the customs Office,
Now see the thread where I had explained my probs and found this mechanic: https://www.pakwheels.com/forums/cng/185248-annoying-cng-leakage-problem
Plus later I had same air filter cover opening and backfiring issues, got solved from same person. If you visit him, just tell that you have already changed plugs and plug wires. Ask for tariq the elder of bros I guess.. found him good.
Best of luck.
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