Weird backfiring problem please help

[Chaotic_Warlord]

Hey guys, I have this weird problem that my car has recently started to do. I have an S14 with 235K on the engine so I know I'm bound to have issues which I fix as they arise, this just happens to be the newest one. Anyways, let me just say that the car idles and runs perfectly fine, a little hesitation due to the fact I need a tune up but once I get into 4th gear (it's an automatic trans) once I get to highway speeds (above 50MPH) it starts to do this weird backfiring thing. when I'm on the gas it does a series of pops and then when I let of the gas it pops again but it doesn't pop if I'm just coasting, onlye when the gas peddle is pressed and released. It only does this above 50MPH and it's really annoying. Now I did a search but the results came up for backfiring through all the gears. I have a brand new EGR solenoid in so I know it's not that, it does idle rough or bog (not anymore than is expected on an engine this tired). I've run some fuel injector cleaner through it but I know that they may be part of the problem. Basically it sounds kinda like there's a rich spot somewhere in the upper side of the fuel map. So aside from changing the plugs and wires and the fuel filter (all on the list of things to do in the near future) what else should I look at? Is there a way to "reset" the ecu or no? I don't have a CEL light (that went away after the EGR was replaced and I passed my state emmission (except the CO test) which coincidentally is when it started to happen (basically in DE you have to hold the RPMs at 25K for 3 minuntes) I had to subject the engine to this 4 times after that it started doing the whole backfiring thing. So what do you guys think is the problem?

[skydragoness]

Well, seems to me that its a timing issue, which would be part of doing that tune-up your'e putting off. My car was doing some exhaust pops a few months ago and I checked the timing and it was retarded 5 degrees. That's enough to be noticeable w/ my catback (backfires sound like shotgun shots actually). Gas mileage suffers quite a bit with retarded timing too.

I'd do the tune-up and see if that solves the problem.

[Slipstream]

Does it sound like a smal series of pops only on accelerating, and get loud when you let off of the gas? If so it might be an exhaust leak. That's the problem I have now, a small leak at the exhaust manifold. Have the stuff to fix it, just not the time, oh and I'm lazy. It should be finished by tomorrow. Check for blackening around the flanges or have a buddy loojk for small whisp of smoke while you idle it at around 2k.

[Chaotic_Warlord]

Does it sound like a smal series of pops only on accelerating, and get loud when you let off of the gas?

It does exactly that, honestly I don't mind the series of loud pops when I left off the gas but the small little pops when I'm on the gas is just downright embarrasing, it sounds like my car is doing that little single pop fart old people get when they take a step. Like I said the only time it does it is when I'm at 50 and above. So yeah the mini tune up is soon, shoulda did it this week while it was nice, but looks like we should have another warm spell next week, so if next weekend is nice I'll change out the plugs, wires and fuel filter, the air filter will have to wait cause I'm getting an AEM intake early next month. Just been putting it off cause I'm going to have to special order the wires since noone around here has them in stock.

[skydragoness]

^ Don't forget to do your timing. Its crucial.

[Slipstream]

well, replaced the exhaust manifold gaskets, and it stopped the noise. have you had any luck with yours yet?