my daughters mom brought her car (2000 accord 2.3) in the garage to have the flex pipe fixed, car went in running perfect, came out miss firing like crazy. Number 1 and 3 cylinder are miss firing. She lives 2 hours from me so i cannot look at it for her and im not familiar with Hondas like i am with Mitsubishi

Any clue what this could possibly be?

 

Welcome to the HAF site. Did they weld in a flex section or replace the whole pipe? If welded there is a very remote and unlikely potential slag hit a wire. My guess it is just coincidence in timing of work. How many miles are on the car and when was the last major service done? Some initial thoughts without more information are fouled plugs, faulty plug wires or connectors, dirty injectors, EGR ports clogged, etc. iIt could be as simple as a faulty distributor cap and rotor. The 30k service for the car includes cap, rotor, valve clearance inspection and adjustment. If it has a ULEV engine then the plugs should be platinum or iridium tips and replaced every 90 to 100k. If the car has traditional plugs then they should be replaced every 30k. Additionally, for you information the car has a timing belt that should be replace every 100k along with water pump, balance shaft belt and two drive belts.

I hope this is enough insight to get you started in the thought process. That car does not have coil over plugs thus I am inclined to rule out a coil issue. Essentially it is either a spark issue, a fuel delivery issue or EGR port issue.

 

sorry I am limited on the info, its cylinder 4 and 3 which firing order is 1 and 3 for them 2 cylinders, she put new plugs in it, she had some one check the cap and rotor and said they were good, really wish I was there to check, so I cannot tell you if they were in fact good. They welded a new flex pipe in, I had her have her friend look and there is nothing around that area to hurt wiring wise.


she literally just told me them 2 cylinders are not firing at all, I had her friend pull the plugs out and crank it over, they do not spark


oh and it is a ulev vtec engine if that helps

 

If the rotor is bad it can allow the spark to jump across and cause miss firing. If someone has a set of plug wires from a 1994 thru 2001 4cyl. Accord the can swap the two miss firing cylinder wires and see if it goes away. Also, if they remove one of the miss firing cylinder wires from the cap and a test light is inserted, someone can crank the engine and see if the light goes one and off. Be sure that the light is properly grounded and that when it comes on it is bright. Have someone then check all cylinders for spark, it at this point there is no spark at any cylinders or spark is weak then it could be the ignitor has failed. The best way to check for that however, is to check the tach signal.

 

2015 Pilot check engine light comes on and off repeatedly. 100k miles. Dealer suggested replacing belt and all 100K service which we did. Light still goes on for a few days then off. Codes show misfire in cylinders 5 & 6. Sometimes cylinder 4 as well, but we are talking 40 misfires when cold. We have had the plugs and coils swapped, new fuel injectors, swapped fuel injectors and finally valve adjustments. Light still goes on. Especially when engine is cold. Thoughts?

 

If car was running perfect before the flex pipe work I'm wondering if it could be an O2 sensor issue,

On the other note, Jacobgary I don't think you read the forum rules but you should start your own thread and not hijack someone else's
it's a bit confusing for people who are trying to help