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O2 Sensor replaced on car I'm going to buy and now won't run

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Insomniac13

Proven Member
73
1
Apr 21, 2013
Warwick, New_York
I would post this in this thread but I'm restricted to the Newbie forum: http://www.dsmtuners.com/forums/tun...roblem-o2-problem-wiring-leaned-out-idle.html
Sounds similar to the issues they're having.

So I'm going to look at a 90 AWD 5 spd Talon this weekend. It's owned by a friend of a friend. The car was pushing coolant into the overflow under boost, so the owner changed the head gasket. As far as I know that resolved the issue. (Although this is almost certainly 100% unrelated in my mind I figured I'd post about it just in case someone who knows better than me thinks otherwise!)

For whatever reason, I guess the car may have started to run a little rough, the owner replaced the O2 sensor (EDIT: It has a wideband O2 simulating the narrow band input to the ECU) and now the thing runs lean as hell and barely idles! I'm calling him soon to confirm the mods that are on the car, but to the best of my knowledge it has an FMIC, a 16G, a GM MAF and MAFT, a boost controller, and some other little mods. I'll update the list so it's better once I know myself. I believe it has the stock ECU, but it may have ECMlink. Like I said, I'll update as soon as possible.

I would really like to buy this car, the 1GA's are my absolute favorite, and I'm wondering what the hell the issue could be. Anybody have similar issues that they resolved??

EDIT: The car was sitting for a long time before he bought it, then he drove it for a couple of months and then garaged it for the past 2 or 3. He changed all the fluids and did proper maintenance.
 
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I would post this in this thread but I'm restricted to the Newbie forum: http://www.dsmtuners.com/forums/tun...roblem-o2-problem-wiring-leaned-out-idle.html
Sounds similar to the issues they're having.

So I'm going to look at a 90 AWD 5 spd Talon this weekend. It's owned by a friend of a friend. The car was pushing coolant into the overflow under boost, so the owner changed the head gasket. As far as I know that resolved the issue. (Although this is almost certainly 100% unrelated in my mind I figured I'd post about it just in case someone who knows better than me thinks otherwise!)

For whatever reason, I guess the car may have started to run a little rough, the owner replaced the O2 sensor and now the thing runs lean as hell and barely idles! I'm calling him soon to confirm the mods that are on the car, but to the best of my knowledge it has an FMIC, a 16G, a GM MAF and MAFT, a boost controller, and some other little mods. I'll update the list so it's better once I know myself. I believe it has the stock ECU, but it may have ECMlink. Like I said, I'll update as soon as possible.

I would really like to buy this car, the 1GA's are my absolute favorite, and I'm wondering what the hell the issue could be. Anybody have similar issues that they resolved??

Check the wiring at the coolant temp sensor and make sure neither are broken. The wiring is in the same bundle as the o2 wiring so it is very possible that it was broken during the replacement.
 
Check the wiring at the coolant temp sensor and make sure neither are broken. The wiring is in the same bundle as the o2 wiring so it is very possible that it was broken during the replacement.

Thank you so much, I've narrowed it down to this or the throttle cable being out of adjustment but this sounds much more likely! I'll be sure to check it out.

He says there's also tapping coming from the head, would that be related? The thing sat for 2 years before he bought it so I'm willing to bet it's lifter tick, but I'd just like to know if that might mean something.

EDIT: The car has an aftermarket wideband that simulates the O2 sensor, so I don't think that the coolant temperature sensor wiring would be the issue, I won't rule it out though. Open to any more suggestions to look for when I check out the car on friday.
 
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Thank you so much, I've narrowed it down to this or the throttle cable being out of adjustment but this sounds much more likely! I'll be sure to check it out.

He says there's also tapping coming from the head, would that be related? The thing sat for 2 years before he bought it so I'm willing to bet it's lifter tick, but I'd just like to know if that might mean something.

EDIT: The car has an aftermarket wideband that simulates the O2 sensor, so I don't think that the coolant temperature sensor wiring would be the issue, I won't rule it out though. Open to any more suggestions to look for when I check out the car on friday.

I dont really see how the throttle cable being out of adjustment would cause these symptoms. It can either be too tight and make the car have a high idle, or be too loose and make the pedal floppy. WTF

If the lifters are ticking, driving the car around in the upper RPMs would most likely fix that, (unless they require replacement).

I would also consider switching the o2 simulation back to stock, only to figure out and eliminate the problem. I imagine he is running link?

He did just re-install the head though....:|

If the car sat for two years, it may have developed a boost leak or need some fresh plugs/wires.
 
I dont really see how the throttle cable being out of adjustment would cause these symptoms. It can either be too tight and make the car have a high idle, or be too loose and make the pedal floppy. WTF

If the lifters are ticking, driving the car around in the upper RPMs would most likely fix that, (unless they require replacement).

I would also consider switching the o2 simulation back to stock, only to figure out and eliminate the problem. I imagine he is running link?

He did just re-install the head though....:|

If the car sat for two years, it may have developed a boost leak or need some fresh plugs/wires.

I believe he changed the plugs and wires but I'm not sure, if he didn't I'll use the spare set I have to test it out. I'll be pressure testing it on Friday, thanks for the suggestion!

He said the ECU has a chip, I'm not sure if he meant it had link or some other kind of tuning chip... I'll ask again tomorrow. If all else fails I'll pick up a new stock O2 sensor to try out.

The funny thing is that the car ran great two or three days ago after changing the head gasket and he said he changed the wideband O2 sensor and it started running like crap, which makes me feel like maybe the problem isn't age related.

I'm trying to think of all the possible things it could be, so please keep the suggestions coming everyone!

Anybody else got any ideas? I'm starting to think that it's most likely just some intake gasket or something that he forgot or didn't tighten the bolts down on. Still planning on checking it out Friday, still open to suggestions.
 
Resolved, didn't buy the car. Only held 3PSI in the intake but wasn't a vacuum leak, the head was busted.
 
Bummer, that's why you should always do a compression check before buying, if you have the option to. That would be the first thing I'd check, especially if he just replaced the head gasket. Even still, offer him a super low ball and take care of it yourself ;)
 
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