1991 Integra 5spd with roughly 320k. Bone stock (even got the original GS rims with the “ACURA” caps!).
When my car hit the big 300k mark, my o2 sensor went bad, cat went bad, thermostat went bad, radiator began leaking, head-gasket blew, CV boots (both) went bad, pcv valve clogged, distributor crapped and the alternator crapped out. YES! This all basically happened all at once. One by one I repaired everything with my own two hands. I now am stuck on the last issue and need some help. I search these forums and others as well but was not able to find something matching my issue.
My last repair was going to be the cat (I live in cali… damn smog). When I bought my cat and was driving home, out of nowhere my check engine light popped up. Yes! Its a code 43. The problem is… my car runs great now! I have no idle issues, no overheating issues, no rough starts or sluggish driving. I thought it might be a defective o2 sensor (since I just changed it 2 months ago), so I exchanged that and it still throws a code 43. Everyone’s post ive search have either weird driving or idle issues but my car is running solid (feels like I only have 150k miles when I drive it!).
My car does give off TONS of white smoke even while idling. This stuff looks whiter than anything i ever seen. My coolant levels are fine though. I am going to pressure test the cooling system and a combustion leak detector the next day it doesn’t rain just to make sure. I do have a bad cat so I am thinking it relates to the cat and not to something prior to it.
The code 43 only lights up when I drive (basically when the car is at operational temp). Basically when the temp gauge gets into the normal operating temp, it code 43 then lights up. Could it be that have a bad ground connection that is throwing off the code 43 therefore not something specifically related to the fuel system (such as a bad fuel pump)? If I do have a possible bad ground connection, which grounds should i look for?
I also wanted to mention that I do have that huge service manual but its for the DA integra. The problem is that the manual is for a 1992-1993. If I am correct the 90-91 are OBD0 and the 92-93 are OBDI so I am not sure if I should follow the “troubleshooting” because it might not be the same.
Thanks for all help! I promise that when I find the problem/solution, I will post in detail for all those who encounter this issue in the future, thanks!
you should be able to follow most of the trouble shooting out of that manual. the only difference with your system is that your o2 sensor is a single wire signal instead of 4 wire heated o2 sensor. the rest of the system is pretty much identical.
the problem is not going to be related to the cat, as the ecm has no way to monitor after the cat.
is 43 the only code you’re throwing?
how is the fuel mileage?
you say you’re not down any coolant, yet billowing white smoke. what does the smoke smell like?
one of the first tests the manual will ask you to run is fuel pressure.
here’s a dynamic pressure and flow test you can run. install a fuel pressure gauge. start vehicl. at operating temp, pressure should sit between 35-40psi. pressure. now, pinch the vac line connected to the regulator. pressure should rise approximately 10psi. if not, the reg or vac line to reg is damaged. if you see any fuel inside the vac line at the reg, the reg is leaking and must be replaced. now, vac line pinched, snap the throttle with your hand 3 times. the pressure should not decrease by more than 2-3psi at any time during snap throttle. if it does, either there is a restriction, ie, filter (i imagine you changed this when you did that wack or work), or the pump is weak.
see how nice that test is? you’re testing pressure, the reg, AND flow. dynamic testing. doubtful that the problem is low fuel pressure, since you’d be running lean if it were. and running lean would result in misfires. which you would notice. but a good test nonetheless that you should still perform. even if only to cancel it out.
your problem is likely running rich. the car will purr like a kitten with excess fuel. since the o2 was recently replaced, the next sensor in priority would be the engine coolant temp sensor. test it by measuring resistance first cold, then hot. cold, the number should be high. somewhere around 7-10Kohms. hot, the number will be reduced drastically. probably around 10ohms. the exact numbers aren’t that important. if it’s the culprit, it will be reading high resistance when hot. that’s all you need to know.
next in priority would be IAT sensor. similar to the ECT sensor, it will measure high cold and low hot. then, MAP sensor. to test, measure voltage across the ground pin and signal. should be about 1.2v at idle and about 3v key on engine off.
answer those questions for me first, and run those tests
i think after those, if the problem were not identified, you’d want to start checking injector resistance
It was a loose ground at the thermostat housing. I ran into it while re-checking all my grounds before attempting what you laid out. It wasn’t loose as if it was free but loose enough that you could wiggle it and once I tightened it down, the light never showed up again. I waiting before replying just to make sure it was the loose ground and not a fluke. I finally put a new cat on it and passed cali smog as well. I feel like 500k will be within my reach. Thanks for your help.
If anyone gets a code 43, check your ground that connected to the thermostat housing!