brshqushr

Yeah been getting upset with this car. 1998 Civic EX 1.6l. Originally had overheated so changed as far as can remember, temp-sensor, thermostat, head-gasket, radiator and overflow. Was getting oil into coolant. Ran good but MIL stayed on. Got code for IAC-valve but kept driving. 1-week later overheated again. Installed new fan-switch, checked thermostat(good), new spark-plugs, new IAC-valve, had head shaved/milled .004", adjusted rockers/valve clearance, new gaskets again from Domestic Gaskets. Adjusted idle to specs. Pretty sure timing is on the dot for as good as it WAS running. Test drove and ran engine for couple hours until white-smoke dissipated from exhaust and looked normal. Reset codes to 0. Idled high so reset idle again to specs. MIL stayed on again. Tested IAC by book said good. Somewhere hear made sure head-bolts were still torqued to spec and they were. Cleared codes again. Warmed engine again until fan came on. Everything seemed real good. Drove for almost 1 more day, MIL came back on, pulled 02-sensor and catalytic codes. Didn't want to start. And now seems to have same almost original problem except it NEVER overheated this time. I am stumped on how to keep this engine from having this problem. Any input or suggestions? Gene

09chaplak

Can you post the exact codes that are showing now as well as which engine you're currently running? If 98 engine, which D16? If it's not overheating this may be a simple fix but we need codes to diagnose properly.

brshqushr

The engine is a D16Y8. The codes from Autozone were: P050?, P050, P0420

09chaplak

Can you look in here https://honda-tech.com/honda-civic-d...lists-1901557/ and pinpoint which P050x codes you were given? P0420 is your cat not running up to snuff pretty much. How many miles are on the car? You might need to replace it or try some other methods found on youtube for cleaning out your cat. You might be able to get away with just cleaning it and bolting it back on. Is your engine surging? Your IACV might be bad or it might not be seating like it should anymore. When you take it off, look through the gasket and you'll see it's threaded. Get it back to almost seated and make some adjustments from there.

brshqushr

Ok I just went out and warmed it up good until the fan came on. Seems to be running real good. No, it doesn't surge- it did before when the idle was outa wack, but is good now. I will check the things you mentioned and get back in a day or later today. Thanks for now.

brshqushr

Ok, pulled 2-codes: 14 and 67. IAC and throttle-body. Could the throttle-body be losing vacuum? And did you mean remove IAC completely and adjust it? If so from which end- the connector side or the other? The o2-sensor figured it probably needs replaced after running so much coolant past it. I will check the cat soon. Mileage is more than 173,00

NotARaCist

iTrader: (1)

IAC and throttle body? What list are you looking at? 14 is the IACV. Make sure it's plugged in, test it, clean it, and if necessary, replace it. 67 is a catalytic converter code. Check your exhaust for cracks and leaks, focusing primarily around the collectors, as well as the primary and secondary O2 bungs. If there are cracks, either have them welded (short term solution), or replace the part that is broken (long term solution). If there aren't cracks, then consider replacing your cat (correct, but pricey) or installing what's called a test pipe, and use the O2 defouler trick to prevent a CEL (cheap, federally illegal, but if you have feds under your hood, no cat is the least of your worries). Keep in mind, though, that if you take the O2 defouler route, you won't be able to pass an E-test, SMOG, or whatever your jurisdiction calls it, if they do an emissions test.

lostforawhile

if you have a bunch of crud on your O2 sensor from burning coolant, you might be able to take a propane torch to the sensor and burn it off, old trick when people sometimes used to run leaded gas in an unleaded car, thats before most people's time here, it worked to unfoul lead deposits, it should burn off coolant deposits, if the sensor is coated, there may be nothing wrong with the converter, the ECU may just be getting bad data from the sensor

brshqushr

Ok, I will try the propane trick and remove the convertor to clean it. As for what NotARacist said, yes I had/have a crack in the exhaust-manifold this last time had the head off. I thought welded it good but when I tightened the last tiny bit on the last nut heard it recrack through my weld. So, yeah it has a hair-line crack still/again. Can I reweld that again for now while installed using a wire-feed- it's easy to get to it? (until can make sure everything else works good).

NotARaCist

iTrader: (1)

You can try to re-weld it, but those welds never hold up in the long run. The stresses managed to crack through cast metal, and a weld joint isn't going to be any stronger. That crack is what's causing your P0420 code.

brshqushr

Ok, I'll weld it for tempory and do the other stuff to make sure all works then replace the ex-manifold. Thanks! Gonna sign off for tonight until get this stuff done and checked. Thanks again guys!

brshqushr

Ok, got my exhaust welded up and changed the o2-sensor, cleared the codes, warmed it up good and drove around a bit. So far so GOOD! No engine light and runs good. Thanks for ALL your help guys!! Hopefully you won't hear back on this problem again after I replace the exhaust manifold. Thanks again!