Engine problems with my 01' Firehawk

[Sporttster]

Hi and this is my first post on this site. I purchased a used 01' Firehawk a few years back. It now has 33k miles on it, very good shape for its age. The problem is multiple, though. First the history. This car had a tune on the computer done by previous owner to get more HP out of the motor. He also removed both catalytic converters and I'm pretty sure, the O2 sensors went as well. It has long tube headers. He also put a high performace MAF on it, has a K&N filter setup, and I believe that's about it for upgrades on the engine itself. Now the problems.....for one, with a car with so few miles on it it burns oil, about a quart or so a month. Secondly, it's throwing codes for 'Fuel trim bank 1 & 2 condition'. Now supposedly the ECM was programmed when it was tuned to not show codes for the missing O2 sensors and for the majority of time I've owned it, it has not shown a code. Recently, though, it has. So No.1, why would this thing be burning oil with only 33k miles on it and secondly, is this a MAF sensor issue, a ECM issue or something else entirely? Ideas? I've noticed when I'm sitting at, say, a drive through for any length of time, I see a small puff of white smoke out the tailpipe. Sometimes when starting from a stopsign, same thing.

[bigrondownhiller]

When it got a tune they only tuned out the rear O2 sensors which measure catalytic converter efficiency. The front ones are needed for the car to run properly. First clean the MAF sensor. Use CRC MAF cleaner. How many miles are driven in a month? White smoke is water, could just be condensation in the exhaust pipe.

[pajeff02]

As stated above, clean the MAF and throttle body. Use CRC Spray MAF cleaner and do not touch the tiny wires inside as you can easily damage them. When you clean the throttle body, open it up and shine a light into the intake. Chances are that it will be black and oily. The PCV systems on our cars are awful and suck oil into the intake all the time. A good quality catch can is highly recommended. The LS1 is not known to be an oil burner in the sense that oil enters the combustion chamber from inside the engine. This being said, defective valve seals are a possibility, however, I would install a catch can and see what happens. If you want to diagnose the health of your engine, there are three great tools: a compression check, a cylinder leak down tester, and a used oil analysis.

As stated above, with the cats deleted the tuner turned off error reporting for the rear O2 senders. In stock configuration our cars have four (4) O2 senders. Two (2) on each bank above the converters and two (2) on each bank after the converters. The after-cat senders simply tell the PCM if the cats are functioning correctly. It is the pre-cat O2 senders that control fueling.

As far as the fuel trim code, it could be a couple of things. A vacuum leak, a faulty MAF (I am not a fan of aftermarket MAF's), a bad O2 sender that is getting lazy or is not functioning, or poor fuel pressure. Do you have access to any type of scanner that will show real time engine data?

[1998 T/A]

I would almost see who tuned the car if that's possible. Do you guys think it's possible he's getting a lot of oil from the pcv going into the TB? Maybe install a catch can and see if that helps. I've had scenarios where fuel pressure would toss 02 codes my way so check that aswell

[cammed goat]

I agree on the catch can idea.

[Sporttster]

I'll do that, I'll get a catch can installed on this. Hopefully that'll take care of the oil issue. And I've never done the MAF cleaning before so I'll hit the youtube channel and see how that's done. I don't have access to real time analyizing of data. Basically just hit Autozone and asked to have it scanned and that's what it spit out.

[1998 T/A]

A friend if mine has his own shop and I have him read it with his 8000 dollar computer. The auto zone is a quick option but see if anyone in u our area can scan for codes.

[Shermanator86]

Any further news on this? My car has a carbon copy of problems, throwing p0171 and p0300 codes, drinks about 1 quart of oil every change, and even has puffs of white/blueish smoke randomly. I have long tubes, ORY, frost tune, rear 02 delete, air delete, and have already put a catch can on. 01 camaro with 66,000 on it. Would the maf be throwing of just one cylinder bank? From what I've read up on it sounds most like a vac leak but I won't be able to work on it until the weekend.

[Firebirdjones]

Alot of these LS1's have oil drinking problems. I've had 2 that did and 2 that didn't, all were low mile well maintained cars. A couple I had driven well up into the 100,000 mile and beyond range with no change.

Catch can helps catch the oil through the PCV before it re-enters the intake, but it doesn't stop the actual consumption. The rest seems to be mild blowby or lack of decent oil control with pistons that don't fit as tightly in the bores as they should. In severe cases piston slap is heard, mild cases not so much. Either way the oil rings can't do their job with pistons rocking.

My father has a 2002 6.0 truck he bought new and it's used a quart every 2,500-3,000 since it's had single digit miles. Most cases he adds a quart before an oil change. Now 180,000 and still doing the same thing. The 6.0 I had I drove to about 100,000 miles and it never used a single drop, barely would put even an ounce in the PCV catch can after 3,000 miles.

Just hit and miss with these things in my experience, and something you live with, or rebuild it.

When an engine starts using oil at the 70k mile marker and beyond with no previous history of oil consumption I would suspect valve guides at that point. I see excess guide wear in heads that get up in this mileage range from all makes and models.

[raynor139]

May want to check your rear main seal also. That's were my oil was dissapearing to. Noticed the oil pan had alot of oil residue on it. Pulled the seal while the trans was out and it had gone bad.

[pajeff02]

What I thought originally was a rear main on our car simply turned out to be the oil pan gasket. The car used to drip out the trans bell housing and leave a drop or two on the floor. Since replacing the pan gasket it has been completely dry under the car.

[Shermanator86]

Alot of these LS1's have oil drinking problems. I've had 2 that did and 2 that didn't, all were low mile well maintained cars. A couple I had driven well up into the 100,000 mile and beyond range with no change.

Catch can helps catch the oil through the PCV before it re-enters the intake, but it doesn't stop the actual consumption. The rest seems to be mild blowby or lack of decent oil control with pistons that don't fit as tightly in the bores as they should. In severe cases piston slap is heard, mild cases not so much. Either way the oil rings can't do their job with pistons rocking.

My father has a 2002 6.0 truck he bought new and it's used a quart every 2,500-3,000 since it's had single digit miles. Most cases he adds a quart before an oil change. Now 180,000 and still doing the same thing. The 6.0 I had I drove to about 100,000 miles and it never used a single drop, barely would put even an ounce in the PCV catch can after 3,000 miles.

Just hit and miss with these things in my experience, and something you live with, or rebuild it.

When an engine starts using oil at the 70k mile marker and beyond with no previous history of oil consumption I would suspect valve guides at that point. I see excess guide wear in heads that get up in this mileage range from all makes and models.

Yea I've just been checking the oil level every once and awhile and add some when it gets low. My main concern is the codes its throwing and whats causing them, I've read everything from vac leak to plugged injectors.

[Firebirdjones]

171 code is a lean condition on the driver side bank. The 300 code is a misfire, but doesn't tell you what cylinder.

I'd bet these codes are related to one issue. You could try a simple tune up but I always tend to lean towards 02 sensors. After about 40-50,000 miles they need to be changed just like spark plugs, they get lazy, worn, mileage and drivability suffers etc....and can throw codes just like this.

If you felt like experimenting, you could switch the 02's from side to side and see if your lean code switches to the other side of the engine. Either way, I'd make 02's as part of your tune up process anyway, they are likely due for new ones.

[Shermanator86]

171 code is a lean condition on the driver side bank. The 300 code is a misfire, but doesn't tell you what cylinder.

I'd bet these codes are related to one issue. You could try a simple tune up but I always tend to lean towards 02 sensors. After about 40-50,000 miles they need to be changed just like spark plugs, they get lazy, worn, mileage and drivability suffers etc....and can throw codes just like this.

If you felt like experimenting, you could switch the 02's from side to side and see if your lean code switches to the other side of the engine. Either way, I'd make 02's as part of your tune up process anyway, they are likely due for new ones.

02's were replaced when I put my headers on about 10k mi ago, so don't think the would be an issue. Would a vac leak only cause one bank to code? seems like anything to do with the intake forward would make both sides lean.

[SMWS6TA]

What I thought originally was a rear main on our car simply turned out to be the oil pan gasket. The car used to drip out the trans bell housing and leave a drop or two on the floor. Since replacing the pan gasket it has been completely dry under the car.

A lot of guys forget to put some rtv in the corners where the front and rear plates meet with the oil pan gasket. Should be put between the block/plates and gasket.

[Firebirdjones]

I'd still swap the 02's from side to side and see if the issue changes. Electronic parts are never fail safe.

[Shermanator86]

I'd still swap the 02's from side to side and see if the issue changes. Electronic parts are never fail safe.

Worth a try I guess, won't be able to get into the shop until Friday so I'm just trying to figure out where to start.

[Sporttster]

I haven't done much with the car lately. Cash is going towards tuning up our van for vacation this summer so the toy is on the back burner but I'm itching to get it looked into. Found a catch can on Amazon I've been considering buying but what I really need to do is just get the thing in the shop and have them take a good look at it and see what they think it is. Could be the o2 sensors but showing both banks lean makes me wonder. Both o2's go out together?? Going to clean the MAF real good, get some MAF cleaner. Here's a interesting tidbit I didn't share. When I bought the car, I noticed it was making a slight 'tick' sound. Had the oil changed, same thing. Took it to the shop and after much testing, they removed the oil pan and found what looked like cotton seeds from some tree in the oil pan! A clump of it. They thought it might have been slightly starving the top end of some oil. Got that straightened out and the ticking went away. Use Lucas Oil treatment also. So I'm really hoping some of my issue isn't stemming from that stupid cotton seed crap getting into my oil somehow. How on earth did it get in there to begin with??

[cammed goat]

Have you checked the O2 sensor wiring beneath the car to see if the wires are damaged? As for the cotton seed issue, do you know if the car sat before you bought it? If it sat, rodents could have made a nest in the airbox and when the car was fired up, parts of the nest could have been sucked in from the airbox and into the engine.

[pajeff02]

Both banks lean is generally a sign of a vacuum leak, a leak in the exhaust upstream of the O2 senders, or a faulty sensor somewhere.