hi, i bought my 97 civic a few months back. the previous owner did a little work to it. new intake, muffler, paint. i cannot find his phone number and i want to find out exactly what he did to the exhaust system. I know there's a new muffler, because it sounds different, but i want to know if he did anything to the exhaust and headers. how do i tell the difference by looking at it? if i need to provide more info please let me know.

 

Post pictures.

 

^x2

 

hope these help

 

Stock header. exhaust shop made an exhaust for it looks like 2.25 or 2.5 inch

 

piping is new. hard to tell diameter from pics. header is OE, your car has a cat on manifold. is this a civic hx? i ask because of the EGR valve. if it is, an exhaust/ intake might actually hurt your mpg.

 

Revert the car to stock.

 

sweet, thanks a lot. I dont know what model it is. 2 door , its not a hatchback. all the labels were taken off before it was plastic coated. I took it from colorado to cali and back 57 gallons 2470 miles 43 average mpg for the trip. that's with rush hour traffic driving through LA. no complaints on the gas mileage. any tips or tricks on efficient, inexpensive (college kid) power? yes grumblemarc i did read your links on placebo power from intake/exhaust/headers, but i'm all about placebo if i think i'm going faster.

 

X2

Start with the intake.

 

VINs were removed?

Check the block code - you should see D16Y5.

https://honda-tech.com/forums/showpo...5&postcount=12

 

Sounds like an HX! Also looked like a 4-wire O2 sensor, which indicates HX, correct?

 

Manual HX has 7-wire and CVT HX has 4-wire.

 

body says CP. its a 5 speed manual

 

For security, you may want to truncate the VIN or not post it all. Just the car information and EJ7 is sufficient.

4- or 7-wire primary O2 sensor?

 

ok thanks, VIN removed. i really have no idea what EJ7 is, or if it is a 4 or 7 wire (guessing O2 is oxygen? sensor), or how to check. i'll do some research on some stuff and post any future questions.

Thanks for the help everyone.

 

EJ6 - CX, DX, LX with D16Y7 engine
EJ8 - EX with D16Y8 engine
EJ7 - HX with D16Y5 engine
EM1 - coupe with B16a2 engine

 

Theres a vin in your engine bay by the firewall

 

keep all the placebo power you want, but please buy a set of OEM NGK wires. those ridiculous things on there will hurt both your power and mpg. Hondas are picky about ignition parts.