Hi All, so my 2002 Firebird TA has had a hesitation issue since I got it, not bad but annoying. I cleaned out the throttle body blades after changing the air filter (Wix 46144) the hesitation was still there but seemed better. Last weekend I changed the oil/oil filter, and drove it an afternoon to get the oil circulated then the car sat most of the week. This morning I started it up and got a Service Engine Soon light, code reader showed a P0101. It was humid and rained this morning during my drive. I filled up the gas tank and reset the oil/trip counter to reset the oil change interval (held it down for 12 seconds and the change oil light flashed a few times). The code is still listed but the Service Engine Soon light went out. The car is idles fine and the air flow at 35 MPH and 2000 RPM was between 2.4 and 4.3 Lbs/Min. At idle its around 0.8 Lbs/Min. Is this "normal" and did my resetting the change oil somehow cause the dash light to go out?

I stopped off at the local O'Reilly's as I was super close by and they only had the Blue Streak MF8308N 3 terminal onsite and it includes the whole thing, not just the sensor. I haven't heard of this brand and the order options are the cheaper all plastic MF8308 (I won't consider this), Delphi AF10056 plastic with 5 terminal and pig-tail, Spectra Premium MA101 3 terminal, and an AC Delco Blade only terminal 213-3457. The ACD looks different than the other options as it doesn't include the plug in terminal. Has anyone used the Blue Streak or Spectra before? Should I try cleaning it again as last time I didn't unplug the wires or remove it from the intake manifold. The car has just over 45k original miles and was stored for quite some time so I know there is some deterioration of parts.

 

I would use the AC Delco as their sensors always seem more dependable than others. Many here will attest to this.

 

Should be able to find a resaonabley priced MAF on the big auction site.

 

Decided that given how dirty my throttle body was, and the age of the car, I should at least try to clean the MAF first, worst case I'm out $10 for a can of cleaner and the 30 min to give it a shot. Well, I got it mostly apart. I could not get the lower half of Ram Air box off the MAF. It could rotate and seeing how stiff the plastic is, and old, I didn't want to pry on it too much. So I ended up cleaning it with part of the air box attached (The CRC MAF cleaner stated it was safe for plastics). I found a small bug and piece of microfiber towel lint on the grid opposite the 3 electrodes. They would not come out with the pressure from the cleaner can so I delicately pulled them off with small needle noise pliers (never touched the grid). I sprayed the grid, electrodes, and metal parts a few times, wiped off the excess careful not to bet too close to anything delicate and then used the opportunity to clean the inside and outside of the air box, hoses, and clean the throttle body again. Put it all back together and started the car up checking the codes and the MAF code was still there (no dash light). I cleared the codes and let the car idle for a about 5 minutes. (I had driven the car for 10 minuets before taking it all apart). Started it back up and took it on a 30 min drive in traffic, it seems to be running different (better) but I will have to monitor it.

Earlier in the week, before this cleaning today, I noticed the hesitation was getting as bad as it was before cleaning the throttle body. After cleaning the MAF the quick 5 min drive I did I tried 2 hard passes on a straight away and no hesitation through the first 4 gears. On my 30 min drive it seemed to adjust idle down a bit and throttle response is a lot more sensitive. Unfortunately my code reader is an el-cheapo and the live data read is limited and can't be saved so I can't compare what it was before to what it is now. The MAF readings look similar as to temps and the advance is moving from 18 to 25 degrees. No codes were active or pending since clearing after the cleaning. Exhaust doesn't smell as rich as before but the car was warm and its a nice day here in TX so I'll wait for a cold start in the morning. This is possibly the first time the MAF was cleaned so, would that make a difference and would this be the source of my hesitation and fuel rich issue (oil reeked of gas when I changed it last weekend). The inside of the air box was clean-ish with some ash I got off with a towel (careful not to get any lint in there). Air filter has less than 800 miles on it. I cleaned the inside of the hood scoops and air deflector and they were really dirty. I hope the hesitation doesn't come back because it was really annoying and the rich exhaust/smell in the oil concerned me because I know that will wear down the internals of the engine if not fixed.

 

Do you have a K&N filter? If so, throw it in the trash. I like my AEM Dry Flow filter and I know it won't screw up the MAF.

 

I don't think ANY oil-wetted filter has a place on a MAF equipped engine. Too much chance of fouling.

 

I am using a WIX 46144 conventional filter. I am not a fan of K&N filters or their "cold air" systems inside the engine bay, the factory Ram Air is a true cold air intake as it comes from outside the engine bay. I honestly believe some of the detailed maintenance items on this car were neglected. Last night I went out for another 45 min drive and it ran great. This morning it ran smooth and accelerated without hesitation on a hard run. I know I am at best buying time before replacement as electronics, especially 19~20+ year old ones will break down eventually.

 

I had this problem when I first bought my car. K&N filter fucked up my MAF and had red oil all over my throttle body. Cleaning the throttle body and MAF temporarily fixed it but the hesitation and code came back just like it did for you. Switched out the MAF for the AC Delco plastic housing MAF (and never touched a K&N filter again) and I've never had the problem since then. Hope that helps.