Potential electrical problem causing sparks along exhaust pipe?


Asked by Feb 01, 2016 at 11:28 AM about the 1999 Honda Civic Coupe EX

Question type: Maintenance & Repair

Just noticed the strangest thing while fixing a broken exhaust pipe. When
we went to start the car to check the repair, we noticeds the area of pipe
that is near the heat shield under the gas tank sparks!! (not even in the
area of the fix). We never noticed this before, anyone ever heard of
something like this? We are assuming an electrical short, have already
disconnected both O2 sensors to rule it out, still sparked. Only happens
when the car is started. Any tips as to where to start to isolate this

7 Answers


look at all the wiring in the area for damaged insulation.

1 of 1 people found this helpful.

Thanks, we will, the only thing is, we are talking sparks way towards the middle - to the back on the exhaust pipe. All wiring would be up at the front. Any particular area that you can suggest as a starting point? It's really weird!


Are you sure it is an electrical spark and not sparks from hot gas leaking out of a small hole in the exhaust pipe?


Car was being worked on all day, so it was cold. Only started it up to be sure exhaust was no longer loud. Only reason we even saw it is because we were down on the ground looking underneath it. Basically there is a heat shield between the pipe and the gas tank. When car is started, the shake of it starting is enough that the pipe makes a brief contact with the heat shield, this is when the spark occurs. Once running it goes away because contact is no longer being made we assume. It's a white spark if that helps. This area is past the middle but before the rear axle.


Your exhaust system may be building up a static charge that arcs to the nearest metal contact. Try grounding the exhaust pipe with a piece of wire and then observe that spot again. If there is no spark then it confirms my guess. I can't think of any harm this would cause though.

1 of 1 people found this helpful.

I had that thought as well, we will give it a try tonight and let you know!

1 of 1 people found this helpful.

One more question - we sealed the pipe with jb weld, which in hindsight we should not have used because it wont hold up to temperature - ever heard of that causing static? Again, sparks are not any where the fix was.

Your Answer

Civic Coupe

Looking for a Used Civic Coupe in your area?

CarGurus has 10,379 nationwide Civic Coupe listings starting at $750.


Honda Civic Coupe Experts

  • #1
  • #2
  • #3
View All

Related Models For Sale

Used Honda Civic
389 Great Deals out of 51,733 listings starting at $1,200
Used Honda Accord Coupe
99 Great Deals out of 4,365 listings starting at $800
Used Honda Accord
607 Great Deals out of 92,577 listings starting at $1,495
Used Ford Mustang
325 Great Deals out of 38,826 listings starting at $1,995
Used Toyota Corolla
713 Great Deals out of 67,214 listings starting at $1,599
Used Toyota Camry
878 Great Deals out of 72,654 listings starting at $1,400
Used Chevrolet Camaro
266 Great Deals out of 30,432 listings starting at $4,200
Used Mitsubishi Lancer Evolution
6 Great Deals out of 534 listings starting at $14,000
Used BMW 3 Series
959 Great Deals out of 33,065 listings starting at $1,300

Used Cars For Sale

2015 Honda Civic Coupe EX For Sale
13 Great Deals out of 344 listings starting at $8,880
2014 Honda Civic Coupe EX For Sale
4 Great Deals out of 87 listings starting at $7,400
2013 Honda Civic Coupe EX For Sale
56 listings starting at $5,990

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.